According to the graph, what condition is best for enzyme activity? A. A temperature of 0°C
B. A temperature of 25°C
C. A temperature below 20°C
D. A temperature above 30°C

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