Generate a sentence that answers this question: "melting ice may be formed by".

Answer: temperature changing can cause phase changes

Generate a sentence that answers this question: "Plant population would fail to maintain it's size if".

Answer: as available water decreases , the population of plants will decrease

Generate a sentence that answers this question: "A pack of wolves eat the sheep before a grizzly bear can get to them, what have the wolves done to the bear?".

Answer:
if an animal takes a resource from another animal then that animal competes for resources successfully