GWD T3 Q7 终于找到很全面的解答了！！

Wikidiot

In Scotland, the number of wildsalmon have been reduced because of uncontrolled deep-sea and coastal netting,by pollution, and by various other threats to the fish’s habitat.

A.   number of wild salmon havebeen reduced because of uncontrolled deep-sea and coastal netting

B.   number of wild salmon isreduced because deep-sea and coastal netting is not controlled

C.   numbers of wild salmon hasbeen reduced because of uncontrolled deep-sea and coastal netting

D.   wild salmon’s numbers arereduced by deep-sea and coastal netting that is not controlled

E.    wild salmon’s numbers havebeen reduced by uncontrolled deep-sea and coastal netting.

很多童鞋很迷茫，为什么选E，下面是详细的解释。

题目释义：In Scotland，wild salmon's numbers have reduced by…by….and by…考点主谓一致（agreement） 平行结构（parallelism prediction） 逻辑意思（logical construction）

1. the number of+复数名词，谓语用单数。
   
2. and平行结构。
   

选项分析

• A. have错误，应该是单数。And后面跟了by，前后应对称的用reduced by。同时by pollution的承受者应该是wild salmon，所以the number of wild salmon错误。
  
• B. and平行错误同A。逻辑主语错误同A。
  
• C. the numbers错误。逻辑主语错误同A。and平行错误同A。
  
• D. that is not controlled不如uncontrolled简洁。
  
• E. correct。
  

补充说明Number的用法小结—by Mayanist：几种用法之间区别：非核心词与核心词；number的意义；number与相关成分的单复数一致关系。
 

1. a number of / numbers of + 可数名词复数 + 动词复数
   
2. 可以理解为量词结构，a number of表示一些，numbers of表示大量
   of后面的复数名词才是核心词，谓语动词因此总是复数
   Many students arrived early, but only a number of them worked on their exercises.
   The lake produces a good number of (=a lot of) salmon each season.
   Numbers of birds fly across the lake.
   另外：any number of 用于非正式场合，表示大量
   There could be any number of (=many) reasons why she's late.
   OG237. It seems likely that a number of astronomical phenomena, such as the formation of planetary nebulas, are caused by the interaction of two stars orbiting each other at close range.
   OG152. When the technique known as gene-splicing was invented in the early 1970's, it was feared that scientists might inadvertently create an "Andromeda strain," a microbe never before seen on Earth that might escape from the laboratory and kill vast numbers of humans who would have no natural defenses against it.
   709. The Coast Guard recently redesigned channel markers in the Chesapeake Bay to accommodate large numbers of ospreys, whose huge nests formerly obstructed the lights.
   829. The speculative fever of the Roaring Twenties infected rich and poor alike; great numbers of people were dangerously overextended, credit was absurdly easy to obtain, and most brokerage houses required only ten percent cash for stocks bought on "margin."
   
3. the number of + 可数名词复数 + 动词单数: number是核心词，可以被具体的一个数字表示 可数物品累积起来的数量, 可数名词需用复数形式。这时number是核心词，可以被具体化为一个数字，如50或者100，谓语动词因此总是单数
   The number of students who participated the interview was 100.
   Today's case brings the number of successful prosecutions in the region to thirty-four.
   [这里有个疑问有待考证：是否可以从例子派生出The numbers of girl and boy students are respectively 30 and 70? 如果可以，则规则为：the number(s) of + n.(总是复数) + v.(单数或者复数-取决于number的形式)]。
   OG-verbal-5. A Labor Department study states that the number of women employed outside            the home increased by more than thirty-five percent in the past decade and accounted for more than      sixty-two percent of the total growth in the civilian work force.
   492. Los Angeles has a higher number of family dwellings per capita than does any other large city.
   有人问为什么不选(D) higher numbers of family dwellings per capita than do other large cities. ETS：the plural numbers is incorrect in that there is only a single number of such dwellings.
   这题是什么时候用单数，什么时候用复数number的好例证：ETS的意思是，因为人均住房面积只用一个数值就可以表示了，例如20平方米/人，即number 就是这个数，所以number 和对应谓语动词都用单数。另外，比较级higher表示将LA的number 和其他城市相应的number相比：one number is larger/greater/higher than the other number.
   
4. numbers作为核心词，表示可以被具体化的几个数530. New Jersey has one of the five highest numbers of reported cases of Lyme disease in the United States.
   908. Upset by the recent downturn in production numbers during the first half of the year, the board of directors, at its quarterly meeting, raised the possibility of adding worker incentives.
   因为每个公司的生产指标有很多，所以用复数形式的production numbers。比较题No.492，在那里family dwellings per capita只可以被具体化为一个数。
   这些情况下，如果明确知道有多个数字，就用numbers。再例如Don't judge a team by its numbers.不能仅仅从数字（指标）上判断一个队（的好坏）。如NBA队伍中每个球员都有rebound, assist, turnover, score等指标，球队有胜率，排名等指标。这些指标就是由多个数字表达的，所以即使team是单数，但是its + numbers是最合理的。上面的句子也可以改写为：Don't judge a team by those numbers listed on its website.
   
5. numbers作为核心词，但可以被具体化的几个数倾向不明显
   

OG-verbal-72. The gyrfalcon, an Arctic bird of prey, has survived a close brush with (A) extinction; its numbers are now five-times greater than when the use of DDT was sharply restricted in the early 1970's. 因为动词是复数，所以可推知numbers是number的复数形式，而不是什么固定用法。
TTGWD9-Q7: In Scotland, the (E) wild salmon's numbers have been reduced by uncontrolled deep-sea and coastal netting, by pollution, and by various other threats to the fish's habitat.
另外，一些讨论中说：numbers是复数做"人数，鸟群"讲。Longman字典：Visitor numbers increase in the summer.　游客人数在夏季增加。现代英汉词典：Birds gather in large numbers beside the river.鸟儿一群群地聚在河边。但是显然后面一个例子中in large numbers是做副词用，参见5)。
这一类用法是最难的，还没有找到最有说服力的解释。但是作题的时候，我们可以借用其他方面的线索，排除错误项(e.g.OG-verbal-72)。
in number(s) 惯用法: 如downturn/decline in number(s)，表示在数量指标方面
In number adv., prep., n.总共，在数目上
They were printed in limited numbers.
Young people have been leaving the countryside in large numbers for urban
areas. [leave … for …]
The condors have dwindled to an estimated sixty in number.
48(non-OG). The golden crab of the Gulf of Mexico has not been fished commercially in great numbers, primarily because it lives at great depths – 2,500 to 3,000 feet down.
550. Once common throughout the Western plains, black-footed ferrets are thought to have declined in number as a result of the poisoning of prairie dogs, their prey. 这题主要是考察逻辑关系：black-footed ferrets (is) common throughout …, 只有A正确。
看来in number 或者in numbers在某些情况下，并不需要严格区分，毕竟GMAT时要求找最佳答案。或许550中用numbers也没错。
the number (s) of + 名词单数或者复数 + 动词单数或者复数，表示标号，数字标识
这时number是核心词，number、物品、谓语动词三者的单/复数形式要一致
The numbers of the machine parts A and B are respectively 201 and 203.
机器零件A和B的标号分别是201和203。
派生出The number of machine part A is 201.
这时number与numbers互为单复数的关系。注意，这里。
The numbers of the machine parts are not available. 这些机器零件的号码找不到了。

sarahni

Thanks!

gingnite