G. E.M. is ______ a famous singer______ many teenagers like listening to her songs.
I’ll go to visit my aunt in England ____ the summer holidays start.
My friend is coming to visit us.I’m looking forward ____ him.
The policeman doesn’t think teenagers ____ drive.
—Do you know who the pen ___? –Sorry,I don’t know.
The mobile phone has influenced people’s life a lot since it ____.