--- Doctor, ________ should I take this medicine?    --- Twice a day. 

I think computers are very useful．They can help us get much      on the Internet．

— Tom, do you want to be a teacher_____________ a doctor?

On March 8th, Flight MH 370 went missing. The news brought great sadness to us,        the families of the passengers.

_______ girl with ____ long hair is Jim’s sister.