5. 由as if和as though引导的从句一般用虚拟语气, 但有时也可用陈述语气.
6. unless从句的谓语动词通常只能用肯定式, unless和if…not同义.

虚拟语气
1. If only he ____ quietly as the doctor instructed, he would not suffer so much now.
A. lies B. lay C. had lain D. should lie
2. What would have happened ______ , as far as the river bank?
A. Bob had walked farther B. if Bob should walk farther
C. had Bob walked farther D. if Bob walked farther
3. It is hard for me to imagine what I would be doing today if I ____ in love, at the age of seven, with the Melinda Cox Library in my hometown.
A. wouldn’t have fallen B. had not fallen
C. should fall D. were to fall
难点：
１． insist作“力言、坚持（认为）时，不用虚拟；作“坚持（应该）做某事时，用虚拟。suggest作“使人想起，暗示” 时，不用虚拟，作“建议”时，才用虚拟。
２． 条件从句与主句的动作发生时间不一致，或者主句是非虚拟语气的句子叫混合条件句。动词的形式要根据它所表示的时间来调整。

巩固配套练习
1. Though he ranked ____ second in the contest, he asked to be given ____ second chance to prove his ability next time.
A. the, the B. /, the C. a, a D. /, a
2. ____ my view, the reporters CCTV 5 gives _____ the Asian Games are of quality.
A. Of…of B. In…on C. As…in D. On…for
3. ---I agree to the proposal you put forward at the meeting this morning. It’s a good one.
---Good one. You _____me when I needed it.
A. should support B. shall support
C. would have supported D. should have supported
4. Many people fail to realize that teaching is an art, ____ needs careful training of a special kind.
A. one that B. whatever C. whoever D. which one
5. Order, please. ____ will have a chance by turn. Please come in ____ after _____.
A. One…one…another B. All…each…another
C. Everyone…one…the other D. Each…one…other
6. It was only ten minutes _____ the sleeping pills did their work and eased his pain.
A. when B. before C. since D. until
7. There was a time ____ the sky was clear and the water was clean here.
A. that B. since C. before D. when
8. The UN official ____ his view that no country could combat terrorism alone.
A. made it clear B. made clear C. made is clearly D. made that clear
9. Shanghai, a vibrant oriental city, won the bid for the 2010 World Expo not long ago, _____ the arduous yet rewarding competition with four other cities.
A. to end B. ended C. ending D. ends
10. Each partner of the couple’s ability to make up for what _____ lacks makes theirs a full relationship.
A. other B. the other C. others D. the others
11. I saw the man _____ down and the driver _____ away.
A. knocking, driven B. knock, driving
C. knocked, driving D. knock, drive