_______ is certain, people’s living conditions in China have improved a lot since the 1980s.
| A．It | B．As | C．what | D．Which |
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 |
Sorry, I am too busy now. If I _____ time, I would certainly go for an outing with you.
| A．have | B．have had | C．had had | D．had |