They had no sooner arrived at the bus station than the bus .
| A．had left | B．will leave | C．left | D．is leaving |
According a recent report, there are _________ to be 1.35 billion people in China in 2017.
| A．decided | B．determined | C．reported | D．estimated |
In the old days, some wealthy people killed animals just for the ______ of it.
| A．joy | B．pleasure | C．fun | D．play |
Xiao Li was about to cheat in the exam ________ the teacher came up, smiling to him.
| A．as | B．when | C．while | D．until |
You can find me easily, for there is only one house _______ roof is flat.
| A．whose | B．of which | C．of that | D．that |
I shall never forget the days ______ I stayed in Africa, ________ has brought me a lot of advantages.
| A．that; which | B．when; which | C．when; that | D．which; that |