How soon will Mrs. Black come back? —” _____.” [ ]
Excuse me, does Mr. Chen live here?—He ______ be here, but he has moved to Nanjing.
Tom wants to be a singer and he_____ singing lessons to do it.
Attention, please. The flight has to be_______ because of the heavy rain.
If you have any problem, you can _________me for help. Which is wrong?