instruction:
In this task, you are given a sentence and a question, you would be asked to create the answer which is contained in the sentence provided.
question:
Sentence: A binary molecular compound is made up of two  elements. Question: A binary molecular compound is made up of two of what?
answer:
elements


question:
Sentence: In weather terms, the boundary between two air masses is called front. Question: In weather terms, what do you call the boundary between two air masses?
answer:
front


question:
Sentence: Expanding gas gas pressure-forces are used to move an object the work is done on the object by. Question: When gas pressure-forces are used to move an object the work is done on the object by?
answer:

expanding gas