Traditionally, college students hold a graduation ceremony to encourage themselves before they ______ on their life journey.（2013 .安徽）
| A．give up |
| B．settle down |
| C．get through |
| D．set off |
Zhangqiang is said ______ the experiment in the lab, but I can’t find him there.
| A．to have done | B．to do | C．to be doing | D．doing |
I’ll go to meet you if I ________ free then.
| A．will be | B．would be | C．am | D．Was |
Jane helped me with my work last week when I asked for leave. ______, I’ll invite her to have dinner with me.
| A．In return | B．In turn | C．In time | D．In vain |
Mo Yan has published dozens of novels, of _____some are very popular among Chinese readers, Red Sorghum, for example.
| A．those | B．whose | C．whom | D．Which |
_____you have to do the job, you should try your best to do it well even though it may be very difficult for you.
| A．Since | B．While | C．Unless | D．Though |