What did Pavlov initially notice about the animals in his original research after conditioning took place? A. They could not smell their food if it was cold. B. They would only eat when he was feeding them. C. They refused to eat food out of a strange dish. D. They salivated even when food was not present. Please select the best answer from the choices provided A B C D.

What is point source pollution of an aquatic ecosystem? a) pollution of freshwater sources b) pollution from many sources that combine into one c) pollution that occurs over a wide area; water that runs off from fields, parking lots, and other land surfaces d) pollution that can easily be identified with a single discharge source, such as an open pipe which drains into a body of water