D. Tertiary
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The answer is shaping. Shaping is normally used to train
animals, such as dogs, to perform difficult tasks; it is also a useful learning
tool for modifying behavior of human. It is a method of training by which
successive estimates toward a target behavior are protected—to test his
theories of behavioral psychology.
Answer:
The major source of pollution that leads to acid rain is factories.
Explanation:
The smokes which are thrown out from factory is mixed up with the rain and cause acid rain.Acid rain can cause various skin problems.
Because they were only interested in themselves
Answer: B. Annual river floods replaced the soil, which improved the crops.
Explanation: Annual floods enriched the soil by dragging nutrients through the water, improving and speeding the growth of crops.
