While Helen ________ the piano，her mother came in．

The meeting _ by the time I got there yesterday.

--- Betty, could you answer my question? --- Sorry, Mr. Green. I didn’t hear you. I _______ about something else.

—Why _________Beijing Duck?—Good idea. Let’s go．　 

 — I called you yesterday evening, but no one answered.      — I ______in my bedroom at that time.