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Chemistry Lessons #3

Advanced Physical Chemistry

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After four lousy boyfriends in a row, chemical engineer Penny Popplestone swears off men until she can figure out why they keep cheating on her. But her no-men resolution hits a snag when the mysterious and superhumanly hot barista at her favorite coffee shop strikes up a friendship with her.

Penny strives to keep things platonic, but when Caleb gives her the kiss of her life, she realizes he wants to be more than just friends. Tired of always being “good little Penny,” she throws caution to the wind and pursues a no-strings fling with the hottie barista. It’s not like they have anything in common beyond scorching physical chemistry, so what does she have to lose?

Only her heart.

Now, this fanfic-reading, plus-size heroine faces an unsolvable problem. What do you do when being apart is unbearable…but being together is impossible?

Advanced Physical Chemistry is the third in a series of standalone rom-coms featuring geeky heroines who work in STEM fields.

274 pages, Kindle Edition

First published March 16, 2018

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About the author

Susannah Nix

38 books1,574 followers
Susannah Nix is a RITA® Award-winning and USA Today bestselling author of rom-coms and contemporary romances who lives in Texas with her husband. On the rare occasions she's not writing, she can be found reading, knitting, lifting weights, drinking wine, or obsessively watching Ted Lasso on repeat to stave off existential angst.

Subscribe to Susannah's newsletter for exclusive bonus content: susannahnix.com/newsletter

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5 stars
643 (24%)
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1,090 (40%)
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765 (28%)
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31 (1%)
Displaying 1 - 30 of 370 reviews
Profile Image for ⊱✿⊰ Alicia ⊱✿⊰ .
550 reviews473 followers
March 8, 2018
4 Latte Love Stars!!

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Penny is a geeky red haired engineer who found herself following a man to a new city, only to find out he is a cheating scum like her past three boyfriends had been. Talk about a massive blow to your self esteem.

Regardless of the crap her ex put her through, Penny manages to find a sweet little life for herself in her new home of LA taking spin classes, yoga and joining a knitting group. She goes to the same coffee shop every morning for her beloved Latte and has a massive crush on hot barista Caleb.

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Caleb was swoon worthy, edgy and secretive at first so I could see why Penny was smitten.

This is the first book I have read by Susannah Nix and I really enjoyed her writing style and all the fun characters she put in this book, I am looking forward to reading more.

All in all this was a sweet, fun, drama free funny at times read that left me smiling.

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Profile Image for Sofia Lazaridou.
2,734 reviews135 followers
March 17, 2018
I was expecting a slightly awkward and dorky book. Something nerdier. I wasn't familiar with the series, so I had no idea what was going on with the book. I was disappointed in the end. The only good thing about this book is that it can be read as stand alone. It wasn't a disaster, but it could have been much better. It didn't have a sentence that made me laugh. And it wasn't overly romantic, so for me, the book promised a lot of things and delivered none. Penny was a decent character and she had some kind of development. I would have liked more if she actually did something when it came to Caleb's hot and cold behavior. One minute he wanted her, the next he didn't and the one after that he did. If the story had been told from his and Penny's point of view I might have liked him more. I might have felt like I knew him even at a basic and shallow level. He just didn't click for me. I don't know if I am in a bad reading phase, but I didn't like the book and I wouldn't recommend it.
Profile Image for SzarlottaSzott.
263 reviews30 followers
November 5, 2021
It was a surprise! Perhaps I’m an easy pleaser these days, but I really enjoyed this story.

It was quite refreshing- probably the only romance I’ve read where the heroine is pursuing a guy (rather aggressively at times) not the other way around. Now if I think about it this approach is not that common in romance books but it is common in real life so I’m glad someone has noticed. Some boys do need a push!

This book (and the whole series) also introduces girls in STEM, but this subject is not developed enough to read “advanced physical chemistry” only for this reason… although it’s always nice to see some representation.

Plus the story is free of unnecessary drama! I do appreciate that!
Profile Image for Siobhan.
4,490 reviews468 followers
March 16, 2018
Advanced Physical Chemistry is the third book in Susannah Nix’s Chemistry Lessons series. It’s a complete standalone, although I do believe we get to see characters from the prior books throughout this one.

Advertised as a rom-com featuring a geeky heroine working in the STEM field, I was instantly intrigued by this one. I love a good rom-com, and I love geeky heroines. Therefore, I went in with quite high expectations. Although this was an enjoyable enough read, it wasn’t quite what I had been hoping for.

I think my biggest disappointment was in relation to the rom-com element. When I think rom-com, I think endless laughter. Most rom-com books will have me laughing every few pages, but I expect at least a chuckle every chapter (not necessarily deep belly laughs, although they’re welcome, just enough to remind me the book is funny). With this one, I did not let out any laughter. There was the slight tugging of my lips a couple of times, but I never let out the kind of giggles I do when reading a rom-com. Some may find this one to be giggle worthy, yet I feel as though the scenes that were supposed to be funny felt as though they were trying too hard which ruined the effect. I don’t know if it was simply a case of this one not being in line with my humour, or whether it truly is a case of false advertisement with the rom-com label, but I do wish there had been more humour throughout.

The actual story was decent enough. I wasn’t crazy about it, but it did keep me turning pages to see how it played out. I wasn’t obsessed about it, but it left me curious, hence my three-star rating. It wasn’t enough to leave me curious about the other books, but I can understand why this one will appeal to many people.

Advanced Physical Chemistry may not have been for me, but it was an okay read to pass a bit of time.
Profile Image for Kate (kate_reads_).
1,337 reviews188 followers
July 2, 2019
I had really been enjoying this series so far but this book was a total miss for me. I really really didn't like it at all.

First - the positive. I enjoyed that Penny is a curvy heroine and while still dealing with some of her insecurities, is really working to take a healthy attitude toward food and exercise. I also love the ways she dove into finding friends in a new place - getting involved in activities that she loves. And...that's about it.

I really didn't like Penny and Caleb's relationship AT ALL. It felt like we just spent most of the book listening to how hot Penny thinks Caleb is. I GET IT. He's hot. Even after he said he's tired of only being recognized for being good looking...that's still pretty much all we get. When she lists the other qualities she likes - he makes good coffee? However - we can't really totally fault Penny for this - because Caleb gives us NOTHING else to like him for.

I hate when characters don't communicate well and not only does Caleb not communicate well, he barely communicates at all. He's a total Jess (from Gilmore Girls) and that is NOT a compliment. Being silent, sulky and moody doesn't make you deep or intelligent. It just makes you boring. What a snooze. And instead of fun banter that I love in a romcom - all Caleb's got is putting a heart in her latte art? Snooze.

In reaction - Penny basically becomes overly pushy and annoying in order to pry any little bit of information out of him. I hate when she basically forced him to take her to his house even when he made it clear he didn't want to. And then while there, she just stumbles across his tuition letter and reads it - no. Not okay. They've been casually dating for a couple of weeks. Also - one of the things I love about this series is that the female characters have careers and it matters to them. Other than Penny once saying that she has to work until 5 because even though she works from home she has to get stuff done - that's about all we saw of her work being important to her.

AND THEN - I also hated how it resolved. Caleb's leaving for med school across the country. Penny is all torn up and feeling bad and trying to make the most of their last few days together. But then he says oh, I decided last week I'm not going. What?? Why didn't you tell her? BECAUSE YOU WANTED HER TO ASK YOU TO STAY???? NO! She wasn't going to do that because for once she's being an actual human and understood that she shouldn't ask you to change your ENTIRE LIFE PLAN for someone you've been casually dating for a few weeks!!!

I will probably give the 4th book a try because I loved the 2nd book in this series so much. I wish I had skipped this one though.
This entire review has been hidden because of spoilers.
Profile Image for Gaufre.
467 reviews22 followers
April 12, 2018
It is more like NA chick-lit than rom-com. Better than the first one. The characters were likable and more developed. I took off a star because it is very slow to get started and another star because there is not much science at all, so it is false advertising.
186 reviews1 follower
August 18, 2019
Disappointed in this, the 3rd in a series, as I really liked the first two. Characters seemed shallow, heroine objectified hero excessively. Hero closed off emotionally and no real insight into why, other than a daddy issue (strict military father stereotype). Ah, well, I will go on to read book 4.
Profile Image for Stephen.
443 reviews51 followers
April 4, 2018
Third in the series. Three stars.

-- Penny: Nix’s best and most rounded character yet. Loved her.
-- Penny’s attempt to move from “nice” Penny to “fun” Penny. Funny. Well done.
-- The romance: Sweet, natural feeling and well developed. Best of the three despite Caleb.
-- The dialogue. More real and conversational. Nix’s writing continues to develop in this area. Now seems to flow naturally from the characters versus from the authors fingers.
-- George. Loveable guy but too small a role. Early on Nix implies that George is a confidant to Caleb (one he sorely needs), but then sadly never develops this plot line. A missed opportunity.
-- Inclusion of side characters from earlier books; e.g. the knitting and yoga crew.

-- Esther. Much ruder and unlikable in this book than the last. So sour that I expected her to announce that her romance with Johnathan from the last book had ended.
-- Caleb. Good character at times then too angsty by a mile. Serious daddy issues for a 23 year old, long since left home. If I were Penny I’d be wary. A lot of long held, suppressed anger in Caleb that the single stand-up moment near the end isn’t going to resolve. Potential time bomb.
-- Nix/Penny’s continual fawning over Caleb’s bod. I get that this is a romance and the male lead typically has to be gorgeous. But Caleb states explicitly in an early conversation with Penny that he hates to be admired only for his looks. This coupled with Penny’s judgments re her own body was an interesting #MeToo role reversal moment. Could have been explored, but Nix tosses Caleb’s concern aside and continues the ogling. In fact, escalates. More ripped abs, biceps and tight butt observations in this book than the previous two combined. Had Nix not voiced Caleb’s concern, I wouldn’t have been bothered. I expect ripped abs, etc. in a romance novel and skim past. But Nix does write that Caleb hates to be admired only for his looks, spotlighting all the later attention paid to his body and I think becoming obligated to respond. Being sympathetic to female characters re objectification, then having a male character raise the same point and ignoring it feels dishonest. Nix didn't require the added erotica in her successful first two novels. She didn't need it here.
Profile Image for 1-Click Addict Support Group.
3,749 reviews442 followers
March 8, 2018
4 Latte Love Stars!!

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Penny is a geeky red haired engineer who found herself following a man to a new city, only to find out he is a cheating scum like her past three boyfriends had been. Talk about a massive blow to your self esteem.

Regardless of the crap her ex put her through, Penny manages to find a sweet little life for herself in her new home of LA taking spin classes, yoga and joining a knitting group. She goes to the same coffee shop every morning for her beloved Latte and has a massive crush on hot barista Caleb.

 photo calebandpenny_zpsvkgcr953.gif

Caleb was swoon worthy, edgy and secretive at first so I could see why Penny was smitten.

This is the first book I have read by Susannah Nix and I really enjoyed her writing style and all the fun characters she put in this book, I am looking forward to reading more.

All in all this was a sweet, fun, drama free funny at times read that left me smiling.

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-Alicia, 4 Stars
Profile Image for Shannon.
4,022 reviews185 followers
November 29, 2021
Another feel-good romance full of vulnerability and swoony love stories. I can't get enough of these characters or this world!! Excellent narration by Caitlin Kelly :) Penny is a plus-sized girl who has the worst luck in love but when the hot barrista shows some interest she takes charge trying not to be just the nice girl, but the girl who can put her own needs first. Highly recommended for fans of All the feels (another romance with a plus-sized, fan-fic loving heroine set in LA).
July 27, 2021
‘She caught sight of the tattoo on his biceps and reached for it.  Pushing up his sleeve to expose the full length of it, she ran her fingers over his skin, tracing the words as she read them:

Transit umbra, lux permanet.

“What does it mean?”

He played with a strand of her hair.  “Shadow passes, light remains.”’

I absolutely loved this one. It was a sweet, slow-burning romance, full of some seriously adorable moments. It was sexy and scintillating, fun and charming.

Our heroine Penny was wonderful. Kind, optimistic, intelligent and forgiving. She was pure in her thoughts and actions. Always wanting the best for everyone around her but never taking much time to ascertain what she wanted for herself. That selflessness was often taken for granted and taken advantage of. Which is why when she finally finds the confidence to go after the something, or rather the someone she wants, things start to heat up in incredible ways.

I know a few readers had an issue with how hot and cold Caleb was. This is probably the first time I've identified more with the story's hero than the heroine. Maybe because of that I was able to understand his slightly brooding, reserved and quiet personality better. I understood why he acted and responded to certain situations. I also developed a better understanding of how it feels to be the other person on the receiving end. It makes us a bit of an enigma when we're withholding the words needed for communication. I loved how deeply he felt for Penny. Even without words it was a palpable thing between them both. The lingering looks, the soft touches, the forehead kisses. Man, those are the best.

This was another superb romance from author Susannah Nix. It's no wonder she's fast becoming one of my favourite writers.
Profile Image for Jessica *The Lovely Books*.
1,219 reviews619 followers
March 14, 2018
Advanced Physical Chemistry was one of the most sweetest books I’ve read this year. Sure, it’s still fairly early with it only being March, but I’ve read a bunch of books. None of them have a more quirky, sweet, and awkward hero than this story. Caleb is absolute perfection—once you get to know him, the more he opens up and shows how amazing he is.

Penny is the main character; she’s smart, beautiful, kind, and I loved that she was a curvy girl. She might not have fit into what society deems perfect but here’s what I say, “to hell with society”! She was the type of woman that if she were to be real, I’d want her as my friend.

The story starts off with Penny catching her current boyfriend stepping out on her. It’s then that Caleb, who works at the coffee shop Penny and all her friends frequent, let’s Penny know that he knew that her boyfriend was cheating on her. Then for some reason Caleb starts opening up and paying more attention to Penny.

He’s attracted to her but doesn’t want to start anything because he’s leaving to go to med school. Which makes him the perfect candidate for Penny, whose on a boyfast, but that doesn’t include sex with no strings attached. Caleb is reluctant about the whole ordeal, until he isn’t. The two were so freaking sweet it caused a toothache.

I’m so happy Penny was the character we got to know. It was nice being able to see someone we can truly relate to. She’s nerdy and into fandoms; that makes her the shit in my book! This is a book that starts off as friends, then friends to benefits, and then... maybe more :)

*Thank you to the author for providing a copy for an honest and unbiased review. All thoughts and opinions are my own.
Profile Image for ally.
Author 1 book25 followers
February 28, 2022
not sure how to rate this one tbh

to start with, the story has its flaws and if it was for the male love interest in real life, caleb definitely exerts some kind of red flags to me. he’s cute, and i feel like he has an (social?) anxiety disorder—although never openly stated—so i get where his behavior coming from, but his difficulties with open communication were driving me nuts. the way penny, the fmc, was obsessed with his "perfect" body while struggling with her own insecurities felt kinda weird to me, but then again, i’m also not so focused on muscles or beauty standards in general when i like someone so ? maybe it’s my own preference here. it’s just feels weird to have more and more diverse, not so perfect female love interests in books noawadays (which i love) but the male love interests stay as "perfect" (cough) as they’ve always been. kinda hypocritical, if you ask me.

then again, it was a cute little love story, good for in-between readings to relax a little and distract yourself from what is going on in the ukraine right now (honestly, no dystopian sci-fi novels for me right now, the real world is already displaying them with real-time videos of dead bodies and way too young captured soldiers).

i like the idea of female scientist as protagonista and the title though, so i’ll definitely take a look at the other books of the series tho 👀
Profile Image for Lindsay.
1,260 reviews222 followers
February 3, 2020
Our main character this time is Penny Popplestone, a chemical engineer working on patent reviews. As she works at home, one of the ways she tries to maintain a routine is to visit a local coffee shop every day. She develops friendships with the staff and the other regulars, but one particularly attractive barista, Caleb Mayhew seems oddly hot and cold. Penny has been burnt by bad relationships before, and Caleb has issues of his own to overcome, but the attraction between them is impossible to ignore.

The theme of this series is women working in STEM fields, which is laudable, but at by far its weakest in this one. It's still a fine romance story besides.
Profile Image for Natalie Dee.
285 reviews1 follower
June 7, 2019
DNF’d the first in this series, but this was available immediately from my library on audiobook so I though I’d give it a shot. And I am glad I did! It was pretty fun, and packed more of an emotional punch than I expected
Profile Image for Mia.
2,228 reviews530 followers
August 26, 2021
What I leard quickly was despite interesting blurb, this was anything but interesting. In end boring and tiresome.
Profile Image for Cassablanca.
37 reviews
June 6, 2022
Loved it. I started reading it because of the STEM fmc, but really liked the story. The main conflict was very relatable. And I loved how the fmc was the one who set the pace of the relationship.
Profile Image for Leigh Kramer.
Author 1 book1,173 followers
March 16, 2018
I positively inhaled this story! Susannah Nix creates such relatable, interesting characters that I simply had to know what would happen to Penny and Caleb.

At the heart of Nix's novels are heroines who work in STEM fields. Penny is a patent examiner, who was good enough at her job to be allowed to work remotely in LA. After her fourth boyfriend cheats on her, Penny decides she needs to figure out why this keeps happening to her and I loved the self-reflection that occurred throughout the story. 

She realizes she rearranges her life to suit men, even men she doesn't particularly care for, and that she needs to shut that behavior down. This empowers her to take chances, ask for what she needs, and reevaluate her life choices. There was some really great character growth as the story developed.

I liked that she's a plus-size character but her focus is on eating healthy and exercising. She's at a good weight for her body, even if it doesn't meet societal norms, and she's accepted this but still deals with lingering self-esteem issues. I thought this aspect was handled well.

"He looked like he should be followed around by a key light and a menagerie of cartoon animals." p. 26

Penny doesn't think she has a chance with Caleb, aka the Hottie Barista at her local coffee shop. I so understood this! Caleb is a more mysterious figure at first and getting to know him was like opening a good present that kept getting better. He was such a dream of a man. When Caleb kisses her out of nowhere, Penny has to rethink the way she views herself, as well as him. I think that's why I found their burgeoning relationship to be so delightful. Plus, that first kiss was swoon-worthy as hell.

Because there's a time limit on their fling and Penny's no longer making accommodations for men, there's potential for miscommunication and developing unrequited feelings. Sometimes this made me laugh and sometimes it made me wince or broke my heart but I was always, always with and for these characters. I especially loved seeing how Caleb felt about Penny and the ways they were good for one another. I just kept rooting for them to take a chance on one another and I loved how this ultimately played out.

I really wish Antidote was near where I live because I would frequent it all the time. I loved all the regular customers and the staff that worked there, as well as the off-menu drink Caleb only makes for Penny. I especially loved how George, this lovable curmudgeon, factored into bringing Penny and Caleb together. He was one of my favorite characters and I now wish to have a George in my life.

We also have to talk about how great Penny's friends are, especially her knitting group. I loved how they supported one another no matter what. I really appreciated the way Nix showed that it's possible for the friends to be happy for one another, while also being sad for themselves, depending on their circumstances.  So true and so relatable.

This book made me so happy! The ending was completely satisfying and I can't wait to see what Nix writes next. The world needs more of her brand of smart romance.

Disclosure: I received a complimentary copy from the author in exchange for an honest review.
Profile Image for Thenia.
3,853 reviews168 followers
March 11, 2020
The story of Penny, a chemical engineer that has bad luck with men, and Caleb, the barista at her favorite cafe that she has a crush on.

After finding out that her latest boyfriend had been cheating on her, Penny is determined to just have some fun instead, and when mysterious, laconic Caleb starts paying attention to her, she decides that he would be the best person to have fun with.

Caleb is reluctant to get close to her, knowing that . The two become friends and then friends with benefits but no matter how much they try to avoid developing feelings, they soon fall in love.

A light, sweet story that I felt a little too old for, since , something that was a little more New Adult than I wanted or expected to find in this book.

Previous book reviews:
Intermediate Thermodynamics (Chemistry Lessons, #2) ~ ★★★ (21/09/2018)
Remedial Rocket Science (Chemistry Lessons, #1) ~ ★★★★ (08/07/2018)
Profile Image for Robyn.
827 reviews132 followers
September 2, 2018
3.5 that I’m rounding up. I’d like a little more of the male perspective in this series, but Penny is so wonderful!
Profile Image for Bri.
Author 1 book177 followers
July 2, 2021
~3.75 stars rounded up~

I enjoyed this short romance. I identified strongly with Penny: determined, thoughtful, creative and HAS INTERESTS AND FRIENDS OUTSIDE OF DATING. Also loved the fat positivity, though the harping on Penny’s healthy diet was…a choice. Like yes fat people can eat healthy too duh, but no food is evil or immoral!!! Fat people can enjoy all foods!! Anyway.

Caleb was broody and guarded quite a lot, which got a little annoying towards the end, but in general it worked for the dynamic of the relationship. I kinda liked that Penny was the one who seduced him, and he was nervous about falling for her.

I def want to check out the other books in this series.
Profile Image for Lissy.
112 reviews3 followers
June 14, 2022
I'm glad I didn't have any expectations going into this book. Some parts were so cute and I really thought this might be a 3 star read for me but some parts were so... creepy and made me uncomfortable. And there truly was no substance to this story. Just very basic. Cozy if you were looking for something low-key.
Profile Image for Evie.
227 reviews6 followers
July 28, 2019
This book won the contemporary Romance at the 2019 RITA awards. Quick romance read. Really liked the characters. I recommend it for a fast enjoyable read.
Profile Image for JenReadsRomance.
295 reviews1,483 followers
July 14, 2019
The heroine is Penny Popplestone. She works from home but has a favorite local coffee shop. One night she's there with her knitting group when she spies her boyfriend with another woman. She flees to the bathroom where she's comforted by the hottie barista, Caleb. Caleb is shy, quiet and she's always thought he was cute. She realizes he's been noticing her, too.

Pluses: The writing is **very sharp**. Several times I stopped to admire a particularly pithy turn of the phrase. Penny and Caleb are both likable nice people.

Wishes: This book felt like 2 different things. The first half is Penny dealing with the break-up and crushing on Caleb. It was S L O W.

The second half is their affair in the month before he moves away for medical school. The pacing was do different, it felt like whip-lash. There is nothing wrong with this book, but your enjoyment will depend entirely on how much you like to be in a character's head. This is very close third person POV on Penny.

That first half was too much hand-wringing for my taste, and it felt a lot like women's fiction. The only conflict in part 2 was external...Will Caleb leave for med school? These are nice people with good chemistry and no reason not to be together. The low moment is that he goes away for a weekend and doesn't text much. ¯\_(ツ)_/¯

Verdict: This felt like the way people ACTUALLY fall in love, not romance-novel fall in love. I don't know how else to describe it. You may love that! You may hate it! I have no idea! The writing was good enough to make me stick around.

Copied & Pasted from Twitter as part of a project where I'm reading all the 2019 RITA finalists
Profile Image for Liz Schoenthal.
58 reviews11 followers
June 13, 2019
I freaking adore this book. A size 16 heroine who is real and doesn’t spend the whole book fretting about being “fat”. She just says “this is the size my body wants to be” and eats healthy and exercises because they make her mentally feel better, but not with a constant obsession to lose weight. Also Caleb is amazing. I loved them both. I kept crossing my fingers the whole book thinking “it’s so good please don’t fuck it up, please don’t fuck it up!” And she didn’t. If you want a low angst read with women in STEM, knitting, coffee, and a “hottie barista” please do yourself a favor and read this book.
Profile Image for Jennifer Brown.
439 reviews17 followers
July 8, 2021
DNF @ 17% - why can't a fat character just be happy being fat? Why does she have to prove she's a "healthy" fat by constantly reminding us she eats healthy, exercises often, limits her sugar intake - girl just eat the cupcake. This far in and I have no connection with the characters, no desire to see them succeed.
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