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

[EX Q]: Injuries can be prevented by getting proper rest and recovery.
[EX A]: Injuries can be prevented by getting proper what?

[EX Q]: Chewing insects such as dragonflies and grasshoppers have two many sets of jaws.
[EX A]: Chewing insects such as dragonflies and grasshoppers have how many sets of jaws?

[EX Q]: Experiments have shown that acceleration is exactly inversely proportional to mass, just as it is exactly linearly proportional to the net external force.
[EX A]:
Experiments have shown that acceleration is exactly inversely proportional to mass, just as it is exactly linearly proportional to what?