奇怪的GWD 8-41

Q41: When drive-ins were at the height of their popularity in the late 1950’s, some 4,000 existed in the United States, but today there are less than one-quarter that many.

A. there are less than one-quarter that many

B. there are fewer than one-quarter as many

C. there are fewer than one-quarter of that amount

D. the number is less than one-quarter the amount

E. it is less than one-quarter of that amount

原题如上，这道题目我看到大家也讨论了很久很久了。。。但是今天做Prep Test 2遇到了，答案出乎意料是B~!!!

求大家帮帮忙，看看到底怎么回事啊？

没有解释，心有不甘。。。

http://forum.chasedream.com/dispbbs.asp?BoardID=23&ID=106562&replyID=&skin=1

据说as many是一种习惯用法

其他选项错在less和amount都是修饰不可数名词的