1.What will happen to the children if their parents ________ some day?

　　A. break out B. break away C. break up D. break off

2.Under no ________ should you leave this city.

　　A. conditions B. circumstances C. situations D. environment

3.The road was wet this morning. It ________ last night

　　A. must be raining B. By must rain

　　C. must have rained D. have been rained

4.________ I was trying to do is to persuade my brother to give up smoking.

　　A. That B. Now C. What D. Which

5.These results must be accurate, because all the calculations have been done by an ________ computer.

　　A. electric B. electronic C. electrical D. electricity

　　1.【答案】C

　　【解析】break out“爆发”，break away “脱离出去”，break up“破裂，分手”和break off“中断”。根据句意，父母离异应该使用break up。本句意为：如果他们的父母有一天离异，和这些孩子们会怎么样?

　　2.【答案】B

　　【解析】condition意为“条件;情况”，circumstances意为“情况，情形”，situation意为“局面”，environments意为“环境”。under no circumstances固定搭配，意为“绝不，无论如何都不”。本句意为：在任何情况下，你都不应该离开这座城市。

　　3.【答案】C

　　【解析】对过去动作做出肯定推测，需要使用must have done形式。本句意为：今天早上路面是湿的，昨晚一定下雨了。

　　4.【答案】C

　　【解析】题干中，________ I was trying to do为主语从句，故从句需一个连接词，排除B. 从句中空格上的连接词做do的宾语，故排除A。CD按句意选what, 本句意为：我正在努力做的事情就是说服我哥哥戒烟。

　　5.【答案】B

　　【解析】选项ABC为形容词，electric意为“带电的，电动的” electric bike电动车;electronic意为“电子的”，如 electronic computer(电子计算机); electronic mail电子邮件;electrical意为“和电相关的”,如 electrical book(电力相关书籍); electricity为名词,意为“电”。本句意为：这些结果一定是准确的，因为所有的计算都是由一台计算机完成的。