—The plane is due to take off at 7：50 from the airport.
—________ we fail to arrive there on time?
—Try to take another flight then.
A．What if B．As if
C．Even if D．Only if
The traditional view is ________ we sleep because our brain is “programmed” to make us do so.
A．when B．why C．whether D．that
The door burst open and ________，shouting with anger.
A．in rushed the crowd B．rushed in the crowd
C．the crowd in rushed D．in the crowd rushed
Fog ________ the train timetable.
A．upset B．upsetted
C．was upset D．was upsetting
________ we go swimming every day ________ us a lot of good.
A．If；do B．That；do
C．If；does D．That；does
A clean environment can help the city bid for the Olympics，which ________ will promote its economic development.
A．in nature B．in return
C．in turn D．in fact
