review of units 1—3
一. 重点词汇
1. as
as作为连词,引导时间状语从句,“当……的时候”,一般用于一般过去时。
例如:
as he explored the sea,he took a lot of pictures. 他在探海时,拍了许多照片。
还可以引导原因状语从句,只说明一般的因果关系,语气比because弱,说明比较明显的原因,它引导的从句通常放在句首,有时也放在句尾。
例如:
as the car is expensive,we can’t buy it. 由于汽车太贵,我们买不起。
as everybody has come,we can set off. 既然大家都到了,我们可以动身了。
assoonas一……就
例如:
as soon as he arrived in france,he called me. 他一到法国,就给我打电话。
as…as…表示双方程度相等,“和……一样”。
基本句式:
a、主语+谓语(系动词)+as+原级形容词+as…
例如:
xiao li is as tall as his brother. 小李和他哥哥一样高。
your jacket is as new as mine. 你的茄克衫和我的一样新。
b、主语+谓语(行为动词)+as+ 原级副词 +as…
例如:
he speaks french as fluently as you. 他说法语和你说得一样流利。
wang ying teaches maths as conscientiously as her sister.王莹教数学和她姐姐一样认真。
2. a few;few;a little;little
few或a few在句中修饰可数名词,后接可数名词复数;也可用来代替复数名词。其中few表示否定,意为“几乎没有”,a few则表示肯定,意为“有一些”。
例如:
few people lived here many years ago.许多年前几乎没有人住在这儿。
look!you made a few mistakes in your homework. 看!你在作业中出了几处错。
little或a little在句中修饰或代替不可数名词。其中little表示否定,意为“几乎没有”,a little表示肯定,意为“有一点”。
例如:
—how much wine did he have last night? 昨天晚上他喝了多少酒?
—just a little. 只喝了一点点。
hung up,we have little time left. 快点,我们没有多少时间了。
a little还常用来修饰形容词、副词、动词,也可以修饰形容词或副词的比较级。
例如:
all of them felt a little tired.so they stopped to have a rest.
他们都感到有点累,所以他们停下来休息。
lucy runs a little faster than i.露茜跑得比我快一点。
3. a little和a bit
a bit和a little通常可互换,也可修饰动词、形容词、副词。但在修饰名词时有区别:a little可直接修饰不可数名词;而abit则要与of搭配才能修饰名词。
如:
please open the windows.it"s a bit hot.请把窗户打开,有点热。
this morning he only had a bit of milk for breakfast.今天早上他早餐只喝了一点牛奶。
注意:
not…a little意为“非常、很多、不少”,相当于very或quite等;而not…a bit则表示“一点也不”,相当于not at all等。