Lee suffers from insomnia. an undersupply of which neurotransmitter can cause this condition?

Look at the photo of the leaf. which term best describes this leaf?

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat

What noticeable trend from this graph might be used to make a conclusion?