China's first moon rover, Yutu, or Jade Rabbit touched the lunar surface at 9:14 a.m.on December 14,2013, ________deep trace on the loose lunar soil.
| A．left | B．leaving | C．Having left | D．To leave |
20．These flowers need special care ____ they can live through winter.
| A．because | B．even if | C．so that | D．As |
19． The matter has reached to a point ____ the two sides will have to go to court.
| A．when | B．that | C．where | D．Which |
18． My mother ____ for Beijing in a few days. I wonder when the earliest plane ____ on Monday?
| A．leaves; takes off | B．is leaving; takes off |
| C．is leaving; is taking off | D．leaves; is taking off |
17． On yesterday’s interview, he didn’t make a（an） ____ at all; what was the matter with him?
| A．apology | B．change | C．difference | D．appearance |
16．.—Mr Smith, may I ask for a few days off? I am worn out.
--____. We are too busy.
| A．Don’t mention | B．Forget it | C．Don’t worry | D．That’s right |