下面的句子属于“the+比较级, the+比较级”(越……就越……):
The more dangerous it is, the more I like it. 这事越是危险我越喜欢。
The more exercise you take, the stronger you will become. 你锻炼越多,你就会越强壮。
The more expensive petrol becomes, the less people drive. 汽油越贵,开车的人就越少。
请问这类句子哪个是主句,哪个是从句,其中的从句叫什么从句?