instruction:
Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
question:
Some compounds form rigid frameworks called crystals.
answer:
Some compounds form rigid frameworks called what?

question:
Gabbro is a dark dense rock that can be found in the oceanic crust.
answer:
Gabbro is a dark dense rock that can be found in what?

question:
In science, something that always applies under the same conditions is called a scientific law.
answer:
In science, what do you call something that always applies under the same conditions?