—Haven’t we met before?—_______.—But your face seems familiar to me.
The traditional view is ________ we sleep because our brain is “programmed” to make us do so.
The door burst open and ________,shouting with anger.
Fog ________ the train timetable.
________ we go swimming every day ________ us a lot of good.
A clean environment can help the city bid for the Olympics,which ________ will promote its economic development.