TASK DEFINITION: Given a sentence, generate a most likely context or previous statement. The previous statement should be relevant to the given statement.
PROBLEM: Someone has a strange, puzzled look on his face.

SOLUTION: Someone at the cash register, busily ringing the bell.

PROBLEM: People drop what they are doing and flee.

SOLUTION: The train passes by revealing a crowd of men wielding clubs, knives, and axes running towards them.

PROBLEM: He raises it and she grabs a glass off a shelf and hurls it at him.

SOLUTION:
He grabs its barrel and strikes her in the head, snatching it away as she stumbles.