很简单
Mary and May are sister and they are in the same class.Last week they went on a trip to Hawaii.And their teacher asked them to write a composition about the trip.
After supper,Mary began to write in her bedroom.But May doesn't like to write compositions. She watched TV in the living room until 10 o'clock.Then she went to write the composition,but she didn't know how to write it.So she decided to copy Mary's.
Twodays later their teacher asked May,"Why is your composition the same as Mary's?"
May answered,"Because we have the same parents,we went to the same place and saw the same things."
好啦!