Help Detective Barnaby finalize his incident report about a very clumsy suspect.

The suspect _____ on a banana peel, _____ into a fruit stand, and finally realized that a police officer _____ him the entire time.

The correct answer is slipped / crashed / was watching.

We use the past simple ("slipped", "crashed") for a sequence of completed, consecutive events in a story. We use the past progressive ("was watching") for an action that was already in progress in the background while those other events happened.