According to analysts, an alliance between three major personal computer companies and most of the nation’s largest local telephone companies would enable customers to receive internet data over regular telephone lines with speeds much higher than is currently possible.
A. with speeds much higher than is
B. with speeds that are much higher than are
C. at much higher speeds as are
D. at much higher speeds than that
E. at speeds much higher than are
答案为E
疑惑：此题是明显的比较的平行结构，所以比较双方的谓语动词应该是统一的，而companies enable sth to do..thancurrently possible. 所以一这个currently possible 前面不应该是be动词吧？
Between 1990 and 2000 the global economy grew more than it did during the 10,000 years from the beginning of agriculture to 1950.
A. Between 1990 and 2000 the global economy grew more than it did during the 10,000 years from the beginning of agriculture
B. Between 1990 and 2000 the growth of the global economy was more than that during 10,000 years, from when agriculture began
C. The growth of the global economy between 1990 and 2000 exceeds that which had been for 10,000 years from the beginning of agriculture
D. The growth of the global economy between 1990 and 2000 exceeds what it has been for 10,000 years, from when agriculture began
E. The growth of the global economy between 1990 and 2000 exceeded what it did for the 10,000 years from the beginning of agriculture
答案为A
两个疑问：
1.是介词+when 是正确吗？
2.仍然是平行结构：但是during the 10000不是应该用完成时态吗？ 作者: 张大猴 时间: 2009-11-30 15:22
我的理解~ 第一道题~an alliance would enable customers to receive internet data over regular telephone lines （that is ）at speeds much higher than are currently possible （that is）at speeds ....是一个定语从句，同时省略主语和系动词，留下表语做后置定语
第二道题~介词+when 不是对的，when是连词 during the 10000表示过去的时间段，所以用一般过去时，这是xdf讲的，白勇语法也有~作者: Boot 时间: 2009-11-30 16:38
1. 应该是at的搭配，CDE比较，C的as错。DE相比之下are补出来更好，D有that没有be动词很不舒服。
2.通过from the beginning排除BD，C的that which算什么结构？E的did无法还原。细细体会一下，原句的意思和CDE的意思略有不同。