I will go for a picnic unless the weather is bad. 除非天气不好，否则我会去野餐。
4. 引导原因状语从句的从属连词：because, as, since…
Since everyone is here, let’s start our meeting.既然大家都到了，我们就开始开会吧。
He isn’t here as he is busy with his work.他不在因为他在忙着工作。
He felt worried because he had lost his purse. 他感到很着急因为他把钱包丢了。
because, as, since 的区别：because用于表示直接原因,回答why提出的问题，语气最强；As用于说明原因, 着重点在主句，常译成"由于"；since表示显然的或已知的理由或事实，常译成"既然"。
如：Water is very important because we can't live without it.
He didn't come yesterday as his mother was ill.
I'll do it for you since you are busy.
5. 引导结果状语从句的从属连词：so…that….,
such…that
It was such an exciting party that we all enjoyed it much.这是如此令人激动的聚会，我们都玩得很高兴。
The weather is so terrible that I don’t want to go anywhere.天气这么糟糕，我哪都不想去。
such…that, so…that, so that 引导结果状语从句的区别：
such是形容词，修饰名词; so 是副词，修饰形容词或副词。
其结构如下：
1) such + a (n)+ 形容词+单数可数名词+that……
2) such+形容词+复数可数名词+that ……
3) such +形容词+不可数名词+that……。
如：
This was such a good film that I went to see it several times.
It was such good books that they sell well.
It was such bad weather that I had to stay at home.
He spoke so fast that I couldn't follow him.
He is such a lovely boy that we all like him.=He is so lovely a boy that we all like him.
注：在"形容词+可数名词复数/不可数名词"结构中，当名词前有many, much, few, little表示数量的多少时，名词前用so。
如：She made so many mistakes that she didn't pass the exam.
6.引导目的状语从句的从属连词so that,in order that, in case等。
注意：这类从句中常常用情态动词may/
might, can/ could, should等，以保证语气通顺自然。
Speak a little louder so that everyone can hear you. 说话再大声点，这样大家都会听见。
He got up earlier than usual so that he could catch the 6:30 bus.他比往常起床早，为的是能赶上6：30的汽车。
I have to be off right now so that I won’t b e late.
我必须马上离开，这样我就不会迟到了。
7. 引导让步状语从句的从属连词：由though, although, even if, even though, however, no matter how/ what/
who等引导。
要注意使用though, although时，务必避免与but连用。
Though it was deep night, he still kept working.虽然深夜了，他仍然在继续工作。
Even though there is a lot of diffi culty, I won’t give up trying.
尽管有许多困难，我也不会放弃努力。
8. 引导比较状语从句的从属连词：than, as…
She looks younger than she is. 她看上去比实际年龄年轻。
He works harder than he did last term. 她比去年工作更努力。
He doesn’t write so neatly as his sister does. 他不如他姐姐写字工整。
宾语从句
在句子中起宾语作用的从句叫做宾语从句。
宾语从句分为三类：动词的宾语从句，介词的宾语从句和形容词的宾语从句。
校长签字：___________。