摘要：学好每科的知识点，对大家会有很大帮助，小编整理了高一英语知识点Unit3-4：句型归纳，供大家参考。

☆句型归纳☆

1. You shouldn't go rafting unless you know how to swim, and you should always wear a life jacket. 除非你会游泳，而且要一直穿着救生衣，否则就不应该去做漂流运动。

该句中的unless引导状语从句。例如：One can't learn a foreign language well unless he studies hard.

unless引导的条件状语从句，一般可以与if...not...互换。还要注意unless引导的从句经常可以省略。

【考例】(200l北京春招)The men will have to wait all day ____ the doctor works faster.

A. if B. unless C. whether D. that

[考查目标]状语从句。

[答案与解析]B 句子意思是“如果医生不快点工作，

这些人将不得不等一整天。”应该选unless。

2. Eco-travel is a way to find out what can be done to help animals and plants as well as people. 生态游可以找到既帮助别人.又帮助动植物的途径。

该句中的as well as是连词，连接两个并列成分。例如: He can speak German as well as French.

常见的用法:

1. well是副词，意思是“好，优秀”，as well as是形容词 同级比较结构。

2. as well as是固定短语，意思是“和”，相当于"not only … but also..."。

3. as well as连接两个并列成分作主语时，句子的谓语动词应该与前面那个名词或代词的人称或数保持一致。

4. as well as还可当作复杂介词用，意思是“除了……之外，还有”;相当于"besides，apart from"。

5. as well，是副词短语，意思是“也”，相当于“too / also”常位于句尾，与too位置相当。

6. may / might as well do sth 表示“还是……的好”。

【考例】(NMET 1994) John plays football ____, if not better than David.

A. as well B. as well as C. so well D. so well as

[考查目标] as well as连接比较状语从句。

[答案与解析]B 该句中 if not better than相当于插入语，起干扰作用，如果不予考虑，原句就变成了同级比较结构 "John plays football as well as David"。

3. Before she could move，she heard a loud noise. 她还没有来得及动弹，就听见很响的声音。

However, before she could think twice, the water was upon her. 但还没有回过身来，洪水便逼近了她。

该两句中的before用作连词，后接时间状语从句。before用作连词，接时间状语从句时，表示“在……之前”。但在不同的语境中，往往有比较灵活的译法。例如: He knocked me down before he saw me. 他差一点把我撞倒，才看到我。