Divisions of the geologic time scale are largely based on A. equal periods of time.
B. major changes in the fossil record.
C. historic fossil discoveries.
D. major events in human history.

currents is the correct answer.

x would be the most and the least would be y because there are more fruit   and seeds than flock z has insects

well for one plants are always the producer, so a is the answer. a wolf is more of the consumer(predator) and the deer is the prey so i know those two are out of the question. also mushrooms are fungi/fungus so a is the producer.