What would you do
c were, would prevent d were, would have prevented
3) i __________ if she _________ me.
a would have overslept , didn’t call b would have overslept, hadn’t called
c overslept, hadn't called d would overslept, didn’t call
4) ---- if he ________, he ________that food.
-----luckily he was sent to the hospital immediately.
a was warned, would not take b had been warned, would not have taken
c would be warned, had not taken d would have been warned, had not taken
5) she _______ to the party if she _______ invited.
a would have gone, had been b would go , was
c would have gone, was d has gone
key: dabba
3.与将来事实相反
例：1） if i were to be twenty years old, i would take the course of computer science.
= i would take the course of computer science if i were to be twenty years old, but i am
not twenty years old, so i will not take the course of computer science.
2) if i did /should do/were to do that , she would feel very surprised.
= she would feel very surprised if i did/should do/were to do that, but i don’t do that, so
she will not feel surprised.
3) if i failed, i would try again.
= i would try again if i failed, but if i doesn’t fail, i will not try again.
题例：
1) it’s quite impossible that it will rain tomorrow. but if it _________, i would still go to the park.
a should rain b would rain c rained d had rained
2) i don’t think that i shall fail. but if i _______, i would try again.
a should fail b would fail c failed d had failed
3) ________ tomorrow, what should we do?
a if it rains b. should it rain c. would it rain d. were it raining
key: aab
注：书面语中，“if”虚拟语气倒装形式的使用：
如果“if”从句中含有 “were, had ”或“should ”时， 则可省略连词“if ”，而把“were, had ” 或“should” 移至主语之前。
例：
1) were i you (=i were you ), i would ….
2) had they not come last time (=if they had not come last time), we would have done….
3) should it rain tomorrow (= if it should rain tomorrow), she would …
注:
1.某些动词后宾语从句中的虚拟语气。
在动词 suggest, insist, order, command, require, request , demand 等后面的宾语从句中， 动词形式一般用 “should + 动词原形，或省略should用动词原形，用以表示一种建议，劝说， 命令， 要求的语气。
