He gave himself a new name to hide his ____ when he went to carry out the secret task.
They ___________ for two hours
Taiyuan,a city in North China,was struck by a heavy snowfall last week,________serious traffic problems.
It was not until the beginning of the twentieth century________to explore space.
A notice was________in order to remind the students of the changed lecture time.
It took________supplies to construct these energysaving houses. It took brain too.