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

Q: A visual "copy" of an object that is formed by reflected or refracted light is called image.

A: A visual "copy" of an object that is formed by reflected or refracted light is called what?
****
Q: Warm and humid temperature and moisture conditions describe an air mass that originates over the atlantic ocean near the equator.

A: Which temperature and moisture conditions describe an air mass that originates over the Atlantic Ocean near the equator?
****
Q: Another measure of the effectiveness of a machine is its mechanical advantage.

A:
Another measure of the effectiveness of a machine is its what?
****