Answer:
According to the “hygiene hypothesis,” the problem with extremely clean environments is that they fail to provide the necessary exposure to germs required to “educate” the immune system so it can learn to launch its defense responses to infectious organisms. Instead, its defense responses end up being so inadequate that they actually contribute to the development of asthma.
Explanation:
They develop on the undersides of leaves.
The answer is a beaker.
~ThePirc
