Americans eat _____ vegetables per person today as they did

答案：A
翻译：美国人每天要摄入比他们实际需要多一倍的蛋白质.
此题考查倍数表达结构.
其一结构表达为：倍数词 + as + 形容词原级 + 名词 + as...
而twice恰好是倍数词,后面就是as much protein as (they...)了.
所以答案A为正解.

B 里面的many后的as不用 因为as...as..的句型是与as they did连用的 不知道你理解了没有

这是主谓宾句型中的原级比较句,比主系表句型中的原级比较要难一些.但还是有记忆方法的.请看由浅入深的句子演示：
I have many books.
I have as many books as Peter does.
I have twice as many books as Peter does.
I have three times as many books as Peter does.
I eat much food.
I eat as much food as Peter does.
I eat twice as much food as Peter does.
I eat three times as much food as Peter does.
如果一样多,比较简单.
二倍以上,结构：主语+谓语（Vt.)+倍数词+as +much/many +名词（作宾语）+ as+比较对象（省略句）

D

考查倍数表达。more than twice as many vegetables as两倍多的蔬菜;倍数要放在as…as结构的前面。句意：美国人现在每天吃的蔬菜是1990年的两倍多。

as.as .后文这里as they did in 1910,已经有个as了,说明前面就缺一个了,而C还是给了两个,D里就一个,与后面构成了AS..as的用法,和more than没关系

倍数的表达主要有两种
以这个题为例
第一种 twice/ three times as much/many sth as .twice as long as sth
第二种 twice/three times the amount sth .twice the length of sth
C 这个表达不对哈 sth的位置不对 你需要记住咯...

A

倍数词＋as…as意为“是……多少倍”。

倍数词＋as＋adj.(原级)＋…＋as…,
A.more than twice as many (注意后面的as)
今日美国人吃得蔬菜是他们在1910年所吃蔬菜的两倍多.

Americans eat __A____ as they actually need every day.
A．twice as much protein B．twice protein as much twice
C．twice protein as much D．protein as twice much
---记住结构：A+谓语动词+倍数词+as …as + B
A是B的某某倍……

选A .
倍数表达法：
 A + 谓语+倍数+the +n.(size/ height/ length……)+of B
 A + 谓语+倍数+as + abj. + as B
 A + 谓语+倍数+adj. 比较级+than B A + 谓语+adj. 比较级+than B+by+倍数
1).This square is twice the size of that one.
 This square is twice as large as that one.
 This square is once larger than that one.
2).This factory produced three times as many cars as they did 10 years ago.
3).He is 3 years older than I- He is older than I by 3 years

A

选A.固定句型：数量词+as.as

选A twice as many
解析：倍数的表达方式之一有：……倍数+as many（或much）+名词+其他+as…,所以选C
倍数表达总结：
1.用形容词表示甲是乙的几倍时,用下面三个句型,用副词表示则一般只用前两个句型.
（1）……倍数+形容词（或副词）的比较级+than
This rope is twice longer than that one．
这根绳的长度是那根绳的三倍.（比那根绳长二倍）
（2）……倍数+as+形容词（或 much）或副词+as
Asia is four times as large as Europe．
亚洲的面积是欧洲的四倍.
（3）……倍数+the size（length,height…）of
This street is four times the length of that street．
这条街是那条街的四倍长.
2.要用名词表示“量”的倍数时,则用以下两个句型：
（1）……倍数+more+名词（可数,不可数）+than
There are four times more books in our library than in yours．
我们图书馆藏书（数量）是你们图书馆藏书的四倍.（我们图书馆藏书比你们的多三倍.）
（2）……倍数+as many（或much）+名词+其他+as…
After the technique was introduced,the factory produced twice as many tractors in 1988 as the year before．
采用新的技术以后,那个工厂1988年生产的拖拉机是前一年（1987年）的两倍.（比前一年增长一倍）

看到句子中as they did ,就可以肯定一定有 as as 句式
这里用as many as
直接可以排除abc
c 改为twice as many 也可以
1."A be 倍数 as 计量形容词原级 as B".
This tree is three times as tall as that one.这棵树是那棵树的三倍高.
His father is twice as old as he.他父亲的年纪有他两倍大.

C.twice as many as

选C
倍数的表达方式：
1.倍数+as+形容词+as...
2.倍数+形容词比较级+than...
3.倍数+the size（length,width,height,depth）of...
此句中twice为倍数,两倍,根据选项,可结合成第一种表达方式

A