686] Tom kept quiet about the accident ____ lose his job.

[译文] 汤姆对此事保持沉默是为了不丢掉工作。

　 A. so not as to 　 B. so as not to

　 C. so as to not 　 D. not so as to

[答案及简析] B。 so as to 中的to 是不定式符号，不定式的否定形式是将not放在不定式符号之前。

685] He wrote to his friends ______ information.

[译文] 他写信给他的朋友寻求信息。

　 A. asked for 　 B. to ask for

　 C. ask for 　 D. asks for

[答案及简析] B。 不定式表示目的。

684] Old McDonald gave up smoking for a while, but soon _____ to his old way.

[译文] Old McDonald戒烟了一阵子，然而不久又死灰复燃了。

　 A. returned 　 B. returns

　 C. was returning 　 D. had returned

[答案及简析] A。 时态题。连词but前后的时态应该基本一致。

683] What _____ to Joan last night? What did she cry for?

[译文] 昨天晚上Joan发生了什么事？　她为什么哭呀？

　 A. was happened 　 B. happened

　 C. was happening 　 D. had happened

[答案及简析] B。 昨天晚上发生了什么事，一般用过去时态；happen不能用被动语气。

682] _____ is the population of your country?

[译文] 你们国家的人口是多少？

　 A. How 　 B. what

　 C. How many 　 D. How many

[答案及简析] B。 就名词population提问"多少"时，可用what或how large。

681] Please say "Hi" to Bob ______ me.

[译文] 请你代我向Bob问好。

　 A. to 　 B. for

　 C. about 　 D. from

[答案及简析] B。 请你代我向某人问好应用say Hi to sb. for me。

680] After we walked ______ the forest, and ______ a river, we arrived at that small village.

[译文] 我们穿过森林，趟郭河流，来到了一个小村庄。

　 A. across; across 　 B. through; across

　 C. across; through 　 D. through; through

[答案及简析] B。 穿过两边有高度的地方用介词through；穿过广阔的海洋，沙漠，平原用across。

679] We were about to leave the classroom _____ it began to rain.

[译文] 我们正要离开教室，这时下起雨来了。

　 A. while 　 B. when

　 C. as 　 D. before

[答案及简析] B。 be about to do sth. when "…正要干某事，这时…"。

678] Three students in ten will go and _____ to stay in the classroom.

[译文] 百分之三十的学生要去，剩下的将留在教室里。

　 A. the rest are 　 B. the rest is

　 C. the other are 　 D. the other is

[答案及简析] A。 rest 可以代替可数名词也可以代替不可数名词，谓语用单数还是用复数就看它代替的是什么名词了。

677] The beef is too expensive. I won’t buy it _____.

[译文] 牛肉太贵，那个价格我不会买的。

　 A. at that price 　 B. at a that price

　 C. on that price 　 D. in that price

[答案及简析] A。 以…价格或速度用介词at。