Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

[EX Q]: A student should use a balance to compare the masses of two small rocks.
[EX A]: Which tool should a student use to compare the masses of two small rocks?

[EX Q]: Moving air masses is the main reason for weather change.
[EX A]: What is the main reason for weather change?

[EX Q]: Gut is the name of the roundworms digestive organ.
[EX A]:
What is the name of the roundworms digestive organ?