Rescuers had to _____ the search because of worsening weather conditions.
| A．call off | B．take off | C．come off | D．cut off |
Mr. Brown arranged for the taxi to come at six __________ he would not have to wait long at the station.
| A．so that | B．even if | C．before | D．because |
__________ this is true in theory, it's very different in practice.
| A．Since | B．Once | C．Unless | D．While |
To everyone's surprise, Michael claimed __________ ail his homework in just one hour.
| A．having finished | B．to have finished |
| C．that finished | D．finishing |
Traditionally, women in China are in red clothes on the wedding day, because red is the __________ of happiness and luck.
| A．logo | B．brand | C．symbol | D．slogan |
He was so proud that he __________ others' help.
| A．turned down | B．turned up |
| C．turned on | D．turned off |