— What should we do to prevent the flu?
—We should keep our rooms_____ and the air fresh all the time.
A. cleaning B. cleaned C. clean
— When did your school hold the sports meet?
—Last week. And I _______ the high jump.
A. joined B. took part in C. will join
— Must we go to see a doctor at once when we have the flu?
—No,_____.
A. we mustn’t
B. we shouldn’t
C. we don’t have to
There____ a baseball game between Class Two and Class Three tomorrow.
A. will have
B. is going to be
C. are going to be
— The flu is becoming terrible these days.
—So we ____ go to crowded places.
A. must B. should C. shouldn’t