He had little idea that it was getting so serious, __________?
| A．didn’t he | B．did he | C．wasn’t it | D．was it |
More than 800,000 Chinese overseas students have returned in the last five years, with the annual number ______ by an average rate of 36 percent each year.
| A．growing | B．grown | C．to grown | D．having been grown |
For most informal dinners, you should wear comfortable and ______ clothes.
| A．official | B．formal | C．casual | D．proper |
Johnson would have faced the music but he ______ doing things like that.
| A．had stopped | B．stopped | C．was stopping | D．has stopped |
How can they learn anything ______ they spend all their spare time watching television?
| A．when | B．though | C．while | D．before |
In this section, we will briefly describe possible ways of reducing the costs and risks ______ in doing this.
| A．involving | B．involved | C．to involve | D．being involved |