Why do all marine algae live near the ocean surface?

It has been said that veterinarians are the world's best doctors, since their patients cannot tell them what is wrong. what are some of the differences between human and animal medicine? what are the advantages and disadvantages of each?

Study the diagram of a desert food chain . what would most likely happen if the kangaroo rats were killed off and removed from the food chain ?

Which process can increase the rate of greenhouse gas emissions into the atmosphere in response to a decrease in albedo