If your good with bio 20 please help with the definition!!!

What is hydroelectric power produced by?

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.

An area has a few days of low humidity, warm air temperature, and high air pressure. what kind of weather is this area experiencing? o fog o snow storms o sun