（1）     GWD-24-Q20

According to a 1996 survey by the National Association of College an University Business Officers, more than three times as many independent institutions of higher education charge tuition and fees of under $8,000 a year than those that charge over $16,000.

A) than those that charge

B) than are charging

C) than to charge

D) as charge

E) as those charging

答案是D还是E??请求解答~~

答案是E啦！

比较主体都是institutions,收8000的institution比收16000的institution多三倍，所以，必须要有those来体现比较的是institutions!