【推荐1】How long do you suppose it is ________________ he arrived and began to work there？

A．when	B．before
C．after	D．since

【推荐2】You have to have a good preparation for the exam__________ you can do well in it.

A．in order to

B．such that

C．such as

D．so that

【推荐3】Why do you turn to me for help ______ you can easily work out the problem independently?

A．until	B．when
C．after	D．unless

【推荐2】Every time ______ they met, they would talk several hours together about the persons and things _______ they remembered in the middle school.

A．that; who	B．when; which
C．/; that	D．which; /

【推荐3】While hosting the Academy Awards, Billy Crystal always keeps a toothbrush with him __________ he started practicing stand-up as a child, he told himself jokes in front of the mirror, brushing his teeth.

A．because when

B．because that

C．when

D．as

【推荐1】 —Professor Smith, I’d like to take a gap year to Africa to serve in a global anti-Aids campaign.
—Good idea, ______ you can afford the time.

A．provided that	B．in case
C．even if	D．so that

【推荐2】Some hard-working students always keep a torch in their dormitories _____ there is a power failure．

A．if	B．unless
C．so that	D．in case

【推荐3】The police officers are on duty during the Spring Festival________people can live a peaceful and happy festival.

A．in case	B．as if
C．in order that	D．only if