As far as we know, half of Canadian teenagers do not get enough sleep on school nights, _____?
| A．do they | B．don’t they |
| C．don’t you | D．isn’t it |
My uncle hasn’t been able to quit smoking，but at least he has ________.(2013·陕西，25)
| A．cut out | B．cut down |
| C．cut up | D．cut off |
In much of the animal world，night is the time________for sleep—pure and simple.
(2013·湖北，26)
| A．set aside | B．set down |
| C．set off | D．set up |
Butterflies________a sweet liquid produced by flowers，which bees and other insects collect. (2013·湖北，25)
| A．carry on | B．feed on |
| C．put on | D．focus on |
According to the law，all foreigners have to________with the local police within two weeks of arrival.(2013·湖北，24)
| A．associate | B．dispute |
| C．negotiate | D．register |
Team leaders must ensure that all members ________ their natural desire to avoid the embarrassment associated with making mistakes. (2013·江苏，29)
| A．get over | B．look over |
| C．take over | D．come over |