So-called green taxes, which exact a price for the use of polluting or nonrenewable fuels, are having a positive effect on the environment and natural resource base of countries as varied as China, the Netherlands, and Hungrary.

a. as varied as

b. as varied as are

c. as varied as those of

d. that are as varied as

e. that are as varied as are

答案a

疑问是前面明明说的是the environment and natural resource base of countries，为什么不是C中的those of 呢？

注解：as varied as 后者用来解释前者，固定搭配。

句子没看懂

as varied as不能看作such as吧。

as varied as是在做类比。意思是“像变化很快的……一样”。句子的暗示的意思是“变化（发展）快（大）的国家的污染比较严重”。varied在这里的意思是“改变了的”，不要理解成“各式各样的”。

那么为什么不是as varied as those of 呢？比较对象要对等啊~~

彻底晕了……

要理解题意。题目的意思是说grean tax是对象中国、荷兰和匈牙利这种变化大的国家的环境和资源有正面的作用。强调的是这样的国家有……问题。国家是用来限制范围的。

如果用as varied as those of ，就变成类比环境和资源。变成“像中国的环境和资源一样的环境和资源”。那谁来限制countries? Countries究竟是指那些国家？

x as varied as y ；

x y 要平行，y在这里解释x

countries as varied as China, the Netherlands, and Hungrary