The ground is slippery. Hold on to the rope and don’t ______.
| A．put off | B．turn up |
| C．let go | D．take apart |
It was in the university ten years ago, _________ they met in September for the first time, _________ they fell in love with each other.
| A．that; when | B．when; that | C．that; where | D．where; that |
Professor Smith, along with his assistant, ________on the project day and night to meet the deadline.
| A．work | B．working | C．is working | D．are working |
Some researchers believe that there is no doubt ______a cure for AIDS will be found.
| A．which | B．that | C．what | D．whether |
If you go by _________train, you can have quite a comfortable journey, but make sure that you get＿fast one.
| A．the; the | B．/; a | C．the; a | D．/; / |
—I would like to pick up your sister for you. But I don’t know her. _____?
—A middle-aged woman with a round face, wearing a red blouse.
| A．How about your sister? |
| B．What do you think of your sister? |
| C．What is your sister like? |
| D．What does your sister do? |