Your tomato plant will grow as long as it gets water. So, if more water is what it needs, why don’t you turn the hose on it, so you can grow an enormous prize-winning tomato? Of course you know that doesn’t work. It’s a question of dosage. Too little and it dies. Too much and it dies too. Tomato survival is low in very dry and very wet environments, but high in environments that are in the middle. Similarly, there are some phenomena that are lower in countries on Level 1 and countries on Level 4, but higher in middle-income countries—which means the majority of countries.
