请教语法题，有争议

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

D, the number 不是说的很清楚吗？为什么不能选

The electronics company has unveiled what it claims to be the world’s smallest network digital camcorder, the length of which is that of a handheld computer, and it weighs less than 11 ounces.

A.      to be the world’s smallest network digital camcorder, the length of which is that of a handheld computer, and it weighs

B.       to be the smallest network digital camcorder in the world, which is as long as a handheld computer, weighing

C.      is the smallest network digital camcorder in the world, which is as long as a handheld computer, and it weighs

D.      is the world’s smallest network digital camcorder, which is as long as a handheld computer and weighs

E.       is the world’s smallest network digital camcorder, the length of which is that of a handheld computer, weighing

此题剩下B,D排除不掉。我觉得B的错误在于which 修饰的是world, 这是不符合逻辑关系的，而且，weighting修饰computer也不合理吧。D的结构很清晰，但是官方答案给的是B。

Scientists have dated sharp-edged flakes of stone found in the fine-grained sediments of a dry riverbed in the Afar region of Ethiopia to between 2.52 and 2.60 million years ago, pushing back by more than 150,000 years the earliest date when it is known that humans made stone tools.

A.when it is known that humans made

C.at which humans are known to have made

A,C争议，说下你的理由

1.

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(it seems awkward to me)

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

2 The next question is difficult for me.I will try my best.

I pick C but I cann give you a reason.sorry

i agree with you largely, thank you

你说的第一题

D中前面是number,后面是amount,一个修饰可数,一个修饰不可数,显然不匹配,况且D中还用了less than 而不是fewer than

你说的第二题

首先,可以排除C/D/E,只能从A/B里面选.因为这题不能用is的形式,只能用to be的形式.原因是用is的形式会产生语法上的歧义这

句话的语法结构应该是

The electronics company+has unveiled +sth.的形式,这里的sth是以what为核心的名词词组

而如果选D的话,就变成

The electronics company+has unveiled +主谓宾齐全的一句句子,主语是what it claims, 谓语是is, 宾语是...

这样,整个意思就发生了改变.本意是"这家电子产品公司发现了据它称是世界上最小的...."

如果选D,歧义就会产生,变成"这家电子产品公司发现,它索赔的东西是世界上最小的..."

一些特征性词,如claim,believe,suppose等等,如果在大主句里面的分句中出现,一般都用to be,而不用is

至于你说的which 必然修饰前面分句中最后一个名词,那也不尽然,GMAT语法题中有好多这样的例外.其实GMAT语法本身并不僵化,是我们人为地总结规律把它变僵化了.关键是看题目的主要考点是什么,次要考点都要服从主要考点.这题主要考点显然是to be 和is的区别,而不是考你which的用法了

你说的第三题如果只能从A/C里面选,那我倾向于C

A太啰嗦

而且容易让人误解成when就是it is known的时间

实际上when是修饰humans made stone tools的时间

C用at which就巧妙地避免了这种歧义