— Where did you find your lost key?
— Well, it was at the hotel we stayed.
| A．that | B．where | C．when | D．in what |
With inspiration from other food cultures, American food culture can take a ______ for the better.
| A．share | B．chance | C．turn | D．lead |
Carbon dioxide, which makes a ______ between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is becoming warmer.
| A．difference | B．comparison | C．connection | D．barrier |
In much of the animal world, night is the time ______ for sleep—pure and simple.
| 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.
| 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.
| A．associate | B．dispute | C．negotiate | D．register |