Once heated是个什么句式?

发布时间:2022-05-11T22:55:22 英语语法

Once heated是什么句式?

人教版新课标英语课本有这样一句话:Once heated, the amber can be made into any shape. “一旦加热,琥珀可以制成任何形状。”Once heated是一个什么句式?

Once heated原本是一个省略了某种成分的从句,补充完整后应该是Once it is heated。再如:When heated, water will become vapor. 加热时,水会变成水蒸汽。



Mary often helped her classmates when (she was) free. (was是系动词)

While (you were) walking the dog, you were careless. (were是进行时的助动词)

John won't come to your party unless (he is) invited. (is是被动语态的助动词)


1. 时间状语从句中,省略“主语+be”:  

When (she was) very young,she began to learn to play the violin. 她很小的时候,就开始学习拉小提琴。

Tom likes to listen to music while (he is) reading. 汤姆喜欢读书时听音乐。

2. 条件状语从句中,省略“主语+be”:

If (he is) given more time, he will do the work better. 如果给更多的时间,他会做得更好。

Unless (you are) here, you can't find this kind of plants. 除非在这里,其他地方你找不到这种植物。

此外,常见的条件从句省略形式:if necessary, if possible, if true, if so, if not, if anyone等。例如:

If (it is) possible, I'll come to help. 如果可能的话,我会来帮忙的。

If (it is) true, this will cause us a lot of trouble. 如果是真的,这会给我们带来很多麻烦。

There are few people nowadays, if (there are) any, who remember him. 现在能记得他的人即使有也很少了。

3. 让步状语从句中,省略“主语+be”:

Though (he is) a young man, he has made several inventions. 虽然还是个年轻人,他已经有好几项发明了。

He is a good man,though sometimes (he is) rather dull. 他是个好人,尽管有时相当无聊。

Even if (I am) invited to,I won't go to such a bad lecture. 即使邀请我去,我也不参加如此糟糕的讲座。

4. 方式状语从句中,省略“主语+be”:

She talked to the stranger as if (she were) absent-minded. 她和陌生人谈话时似乎心不在焉。

He opened the drawer,as if (he was) in search of something important. 他打开抽屉仿佛要找什么重要的东西。

She stood at the gate as if (she was) waiting for someone. 她站在门口好像在等人。

The teacher shouted at the boy as if (he was) angry. 老师朝孩子大喊大叫好似很生气。

5. 比较状语从句省略相关成分:


I know you better than (I know) him. 我对你比对他了解得更清楚。

I know you better than he (knows you). 我比他更了解你。

She can dance ballet just as wonderfully as you (dance). 她芭蕾舞跳得和你一样好。

She has finished the work earlier than (it has been) expected. 她这项工作比预料的提前完成。