As far as we know, half of Canadian teenagers do not get enough sleep on school nights, _____?
A．do they B．don’t they
C．don’t you D．isn’t it
—Is John coming by bus?
—He should，but he _______ not．He likes driving his car
A．must B．can C．need D．may
The athlete’s years of hard working _______ when she finally won the Olympic gold medal.
A．went on B．got over
C．paid off D．ended up
_______ the English examination, I would have gone to the concert last Sunday.
A．In spite of B．As for
C．Because of D．But for
The designer asked _______ we were getting on well with the project.
A．how B．what C．if D．that
Bad habits, _______ formed, are difficult, and sometimes impossible to shake off.
A．before B．once C．until D．unless
