TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: Solids are categorized by the forces holding the individual atoms, ions, or molecules together.

SOLUTION: What is categorized by the forces holding the individual atoms, ions, or molecules together?

PROBLEM: Carried through body happens if cancer cells enter the blood stream.

SOLUTION: What happens if cancer cells enter the blood stream?

PROBLEM: Changes in sunlight or water do plants respond to in their environment.

SOLUTION:
What do plants respond to in their environment?