In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

[EX Q]: Question: What do concentric circles on a topographic map indicate? Answer: a hill
[EX A]: A hill do concentric circles on a topographic map indicate.

[EX Q]: Question: What do craters and rifts become when they fill with water? Answer: lakes
[EX A]: Lakes do craters and rifts become when they fill with water.

[EX Q]: Question: Which event is the best example of competition between species in a pond environment? Answer: frogs and toads eating flies
[EX A]:
Frogs and toads eating flies event is the best example of competition between species in a pond environment.