This is a paraphrasing task. In this task, you're given a sentence and your task is to generate another sentence which express same meaning as the input using different words.
Example: Giraffes like Acacia leaves and hay, and they can consume 75 pounds of food a day.
Example solution: A giraffe can eat up to 75 pounds of Acacia leaves and hay daily.
Example explanation: Input and output sentence have same meaning in different words.

Problem: the professor carefully tried the lock , lest we might not be able to open it from within should we be in a hurry making our exit .
Solution: the professor had tried the lock for a moment , so that we would not have any difficulty in unlocking in a possible hurry .