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

Ex Input:
The location of an object in a frame of reference is called position.

Ex Output:
The location of an object in a frame of reference is called what?


Ex Input:
Certain air pollutants form acid liquid when dissolved in water droplets in the air.

Ex Output:
Certain air pollutants form which liquid when dissolved in water droplets in the air?


Ex Input:
Birds possess a cloaca, a structure that allows water to be reabsorbed from waste back into this?

Ex Output:

Birds possess a cloaca, a structure that allows water to be reabsorbed from waste back into this?