求教prep1-202

Providing initial evidence that airports are a larger source of pollution than they were once believed to be, environmentalists in Chicago report that the total amount of pollutant emitted annually by vehicles at O’Hare International Airport is twice as much as that which is being emitted annually by all motor vehicles in the Chicago metropolitan area.

A. as much as that which is being emitted annually by all

B. as much annually as is emitted by the

C. as much compared to what is annually emitted by all

D. that emitted annually by all

E. that emitted annually compared to the

本题选d，我选的b，求解释，求twice的用法~~

twice 用法

twice as many ...as; twice as much ...as;twice+the+n;twice +what从句

B中much后没有比较的内容,annually 是副词 不能做比较