大全上找不到的XDF的语法材料上的题，请大侠指导

1。section five Q16:

imported into Massachusetts form Europe in 1869,the gypsy moth was used by a French scientist in an attempt at developing a strong strain of silk-producing insects,crossing gypsy moths with adult silkworms.

A.

B.

C.

D.The gypsy moth was imported into Massachsetts from Europe in 1869 by a French scientist attempting
            to develop a strong strain of silk-producing insects by crossing gypsy moths with adults silkworms.

答案选D，我选A，不明白D中的attempting这样用是否可行？印象中attempt都是作名词后面接TO的，请大侠帮忙解答一下

2。section 10  Q7:

when drive-ins were at the height of their popularity in the late 1950's,some 4000 existed in the United States, but today there are less than one-quarter that many.

A.

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 of that amount

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

答案选C，我选E，原因是AMOUNT应该是不可数名词吧，怎么可用复数呢。。 是不是答案有错？

3。section 10 Q10:

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

A.

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 weights

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

答案选B，我选D，我认为weighing这样用不对，大家认为呢？？

4。  再来一个SECTION 10的题目，看来这个部分对我蛮困难的。。。。。

Q 14：

scientists have dated sharp-edged flakes of stone found in the fine-grained sediments of a dry riverbed in the Afar region to 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 know that humans made stone tools.

A.

B.

C.

D.

E. of humans who were known to make

答案选E，我选A。我认为E中的后面的修饰还不如用从句来的简单， 请释疑，谢谢！

眼看要进宫了， 谁帮我一下了。。。。自己给自己先顶着。。。。。。。

其他的carolhide解释的比较清楚了

我多两句嘴

嘻嘻

3。section 10 Q10:

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

A.

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 weights

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

what引导的并与从句，还原一下：it claims 【what】 to be the smallest network digital camcorder in the world,which is as long as a handheld computer,weighing【分词修饰的camcorder】

D：what it claims is the world's smallest network digital camcorder,which is as long as a handheld computer and weights理解成什么呢？what引导的宾语从句里再套一个定语从句修饰what再加上动词is？也就是【what （it claims）】 is ？在舍去修饰部分（it claims）就是这样：the electronics company has unveiled what is the world's smallest network digital camcorder，公司揭示了什么是世界上最小的 network digital camcorder。错了

原句意思是公司公布了他们认为是世界上最小的network digital camcorder；what相当于network digital camcorder

谢谢斑竹大人的逐一解释，全面而周到

感谢楼上大哥的分析，细腻而精彩

谢谢你们

但是，对于最后一道题Q14，如果把IT看成是THAT从句的形式主语可以吗？谢谢！！

it is ...that...?强调你的意思？

强调什么？know这个动作？

我也说不上来，只觉得这样读起来很顺口，不过也许正因为这样所以才是错的吧，现在我想起了石林说的话了，越是口语化的说法就要当心了，因为在“商业英文”当中是非常严谨了。。。

NO MATTERWHAT，TKS FOR YOUR GAYS ABOVE。。。

前面有when了，修饰的date，后面一定是从句，则it必须有所指代

因为it后面有动词know，所以that一定是宾从，这样才合理，这样就剩一个问题，it指代什么

如果是强调句型的话有两个问题

1.强调的对象不对，按意思应该强调的是时间

2.前面有when，后面加强调句型，非常的awkward