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

Ex Input:
Control rods play an important role in the modulation of the nuclear chain reaction.

Ex Output:
What play an important role in the modulation of the nuclear chain reaction?

Ex Input:
In science, something that always applies under the same conditions is called a scientific law.

Ex Output:
In science, what do you call something that always applies under the same conditions?

Ex Input:
Insecticides are commonly used to control insect pests, but can have harmful effects on the environment.

Ex Output:
What are commonly used to control insect pests, but can have harmful effects on the environment?