1. The teacher seldom let an opportunity to teach his students or to help them make up for the days of schooling they had missed __________.
A. pass
B. to pass
C. passing
D. being passed

2. Who do you think he would ________ a letter of congratulation to our monitor?
A. have to write
B. have write
C. have written
D. have been written

3. There is a new problem involved in the popularity of private cars _________ road conditions need ________.
A. that; improving
B. which; to improve
C. which; to be improved
D. where; to be improved

4. Not far from the club, there was a garden, __________ owner seated in it playing bridge with his children every afternoon.
A. which
B. whose
C. its
D. that

5. This is the most expensive dress __________ you can have to attend the conference. Would you like it?
A. on which
B. in which
C. which
D. in that

1.
[答案]A
[答案解析]本题容易错选B和C。这个句子的主干为 “The teacher seldom let an opportunity _______”，这样就很容易看出是let sth do结构，所以应该选pass。to....or to...是opportunity的后置定语，而 they had missed 是作the days的定语。
2.
[答案]B
[答案解析]本题容易错选C。将本题转化为陈述句型是“You think he would ______ sb(who) _______ a letter of congratulation to your monitor.”，由此可看出这里应该是have sb do sth，意思是“让某人做某事”，所应该选B。
3.
[答案]A
[答案解析]本题容易错选C和D。这里第一个空用that是引导一个同位语从句，补充说明a new problem；第二个空要表示“马路需要（被）改善”，这里need doing=need to be done，都有被动的含义，所以第二个空可以填improving或to be improved。综合上述两个空的解释，故只能选A。
4.
[答案]C
[答案解析]本题容易错选B。考查独立主格结构。its owner与seated之间存在逻辑上的被动关系，而不存在主语与实际谓语动词之间的关系。B项干扰性很大，若选B，则应该在seated前加was。
5.
[答案]A
[答案解析]本题容易错选B。本题考查“介词+引导词”的定语从句。这里用on which是因为这个on与从句的have搭配，其实就是have sth on[穿（衣服等）]，所以选A。