instruction:
Given a statement, generate a question such that the answer is contained in that statement.
question:
Non-vascular plants play vital roles as producers in aquatic ecosystems.
answer:
What plants play vital roles as producers in aquatic ecosystems?


question:
Hydrogen and oxygen are essential for all life on earth
answer:
What is essential for all life on earth?


question:
the amount of space an object contains can be used to describe the dimensions of that object
answer:

What does the amount of space an object contains can be used to describe?