语法点：倍数的表达。
1. A has four times the strength of B. - 选项1正确。
2. A has four times as much strength as B (has). - 选项2&3表达都有误。

通过Incorporating补足语可以快速排除选项4&5。

B:
steel has, 主谓结构，一个句子
of后面不能直接加句子，应该把of改成that

A:
is four times the tensile strength of steel 抗拉强度是钢的4倍

B: them指代有歧义，steel后面的has多余
C: them指代有歧义，has four times the tensile strength steel has尴尬，要不像A一样用of，要不像D用as。。as。。
D:incorporates错误，句子里不能再出现谓语了
E:incorporates错误，句子里不能再出现谓语了，比较错误

难题！
学习这个表达： has four times the tensile strength of steel

Chinese public buildings erected under a construction code of the Sung dynasty have withstood earthquakes well
because [the white cedar used has four times the tensile strength of steel] and [the timber frame, incorporating many joints and few nails, is flexible].
根据宋代建筑规范建造的 中国公共建筑 能够很好地抵御地震，
因为所使用的白雪松的抗拉强度是钢材的四倍 ，并且，木结构的接头多、钉子少，具有柔韧性。

代词them指代不明（or不够简洁）--排除BC
一个句子只有一个谓语--排除DE，因为 跟着非划线部分 is flexible，说明这个句子已有谓语is，所以不能再出现另一个谓语 incorporates

C：The connector “comma + and” changes the structure and the logic of the sentence, as we saw in Choice C.
The subject “the timber frame” has two verbs — incorporates and is — but these verbs are not connected by any conjunction.
that was used has four times the tensile strength steel does, and the timber frame incorporates

B：steel has

B这个表达has就最好是用as...as

C
that was used in them ----wordy
strength steel has, and the timber-------should be another 'because' clause rather than a separated clause.

1.Idiom:has four times the.has错，BC多了一个has，BC错。
E同理，后面加了个does也错。E错。
2.句子结构，“，and the timber frame...”把这句话拆成了两个句子，而且这个成分很奇怪，没有谓语，也不能作主语，C 错
and the timber frame incorporates也是同理，把句子拆开了，且这一部分放在这里没啥作用，DE错

because （the white cedar used has four times the tensile strength of steel） and （the timber frame, incorporating many joints and few nails, is flexible）.

B. The construction has four times the tensile strength of steel has is idiomatically incorrect. The correct construction is has four times the tensile strength of steel. 都有xx of steel了怎么还能加has呢。。

the comma after steel breaks up the sentence in such a way that only the great tensile strength of white cedar is offered as an explanation of the buildings' ability to withstand earthquakes, rather than both white cedar's tensile strength and the timber frame's flexibility.

B. The construction has four times the tensile strength of steel has is idiomatically incorrect. The correct construction is has four times the tensile strength of steel. 都有xx of steel了怎么还能加has呢。。

times as many…as
times+ n.(可以是代词，比如 that);times + what 从句
A has four times the tensile strength of steel

C and前加comma，与主句并列，割裂了两个原因

sc
考察：代词，句子结构，并列；比较级倍数，所有格
看了半天没搞清楚为什么句尾出现了is 谓语动词
1.应该是这种结构because （the white cedar used has four times the tensile strength of steel ）and （the timber frame, incorporating many joints and few nails, is flexible）. flexible说的是 timber frame， incorporating作为插入语
2. four times the tensile strength（ of steel and the timber frame）
bc代词them指代不清，赘余；
且b--the tensile strength of steel has 错误应该是the tensile strength of steel所有格

sc
看了半天没搞清楚为什么句尾出现了is 谓语动词
1.应该是这种结构because （the white cedar used has four times the tensile strength of steel ）and （the timber frame, incorporating many joints and few nails, is flexible）. flexible说的是 timber frame， incorporating作为插入语
2. four times the tensile strength（ of steel and the timber frame）
bc代词them指代不清，赘余；
且b--the tensile strength of steel has 错误应该是the tensile strength of steel所有格

cedar比steel和timber frame 的强度大，有joints and nails，cedar很灵活
既然是这样DE就去掉，因为变成了timber frame incorporates。
然后C的 steel has 应该是steel does B里面的used in them的them要找很远才能找到buildlings

parallel.

这里的used是个什么成分啊?? 是white cedar (that is) used难道？that is可以省略？