a lot of常用来修饰可数名词复数和不可数名词，如lots of cakes,a lot of water.这些词都不能修饰可数名词的单数。

例句

1、There was a lot of background noise.

背景噪音很多。

2、We've got a lot of hard work ahead.

我们往后还有很多艰苦工作要做。

3、There has been a lot of resistance to this new law.

这项新的法规已经遇到很多的抵制。

4、You used to see a lot of her, didn't you?

你过去常见她吧？

5、We sell a lot of these to people like yourself.

我们把许多这种东西卖给您这样的人。