---Susan, go and join your sister cleaning the yard. --- Why ___? John is sitting there doing nothing. 

---How many students have visited Yangzhou Museum?  ---____

It is not so difficult to learn English well. ________ you need is listening, speaking, reading and writing it every day.

. --- Sarah said she wrote you a letter. --- I wonder ______ she is writing to me about.

 —Which of the two computer games did you prefer?—Actually I didn’t like _________.