5.5 不用if引导的条件从句
虚拟条件句中的条件从句除用if引导外，还可用when, unless, lest, suppose, as if, for fear, in case, on condition 等词语来引导。
亚马逊导购/好书推荐 
读新闻学外语 
卑诗省当天新盘
The peasants prepared to feed the city when it should be freed.
农民已准备在这座城市解放后供给粮食。
Lest you should not have heard all, I shall begin at the beginning.
我怕你没有听全，所以我再从头开始讲一遍。
Unless I were well, I wouldn’t be at school.
除非我好了，否则我不会上学。
Suppose you were given a chance to study in America , would you accept?
假如给你一个到美国学习的机会，你会接受吗？（suppose 或 supposing =what if）
Supposing it were so？（=Supposing it were so，what would happen？）
要是这样的话，会怎么样呢？
He can use the bicycle on condition that he should return it tomorrow
如果明天能还回来，他就可以借用这辆自行车。
In case I forget , please remind me of my promise
如果我忘了，请提醒我的诺言。
Susan is walking slowly ,as if she were tired.
苏珊走得很慢，就像是累了似的。
与if一样，上述词语所引导的条件从句亦可用直陈语气，表可能实现或发生的事。
