In much of the animal world, night is the time ________ for sleep - pure and simple.
| A．set down | B．set off |
| C．set up | D．set aside |
—What does the sign over there read?
—No person smoke or carry a lighted cigarette, cigar or pipe in this area.
| A．will | B．may | C．shall | D．must |
Walking alone in the dark, the boy whistled to his courage.
| A．hold up | B．keep up | C．set up | D．take up |
It was in the remote mountain areas I spent the gap year I learned how to work with a group of strangers and how to look after myself.
| A．where; that | B．when; that | C．where; when | D．that; where |
--- What are you busy with?
---The exhibition ____ in the city next week．
| A．held | B．will be held | C．to be held | D．being held |
---Jack can't concentrate on his study recently．
--- Yes, that might ____ why he did so badly in the last test．
| A．answer for | B．apply for | C．call for | D．account for |