B:：比较对象不对等
C：which引导的定语从句修饰monkfish错误
D：unlike比较对象不对等，which定语从句修饰错误
E：比较对象不对等，contributing做伴随状语没办法修饰“这里有”
A多读几遍还挺顺的

There are no legal limits, as there are for cod and haddock, on the size of monkfish that can be caught, a circumstance that contributes to their depletion through overfishing.
与鳕鱼和黑线鳕一样，对于可以捕获的安康鱼的大小没有法律限制，这种情况会导致它们因过度捕捞而枯竭。

题目释义： There are……， as there are……， a circumstance that……
没有像鳕鱼和黑线鳕鱼那样有关于捕捞尺寸的法律保护是安康鱼被过度捕捞的原因之一

考点：
1. like/unlike A, S.V.O. 中S与A一定要可比，绝对对称。
2. which/it不能指代一句话，常用同位结构进行替换，例如可以使用discovery/fact等名词总结一句话
3. limit的固定搭配：
n. : limit on sth.; limit to do sth. limit for sb./sth.

错选B 因为觉得A很怪所以不敢选，但实际上B有明显的语法错误，unlike+N需要和实际的名词做比较，但是B选项里unlike的两种鱼比较的是there这种没有实际意义的词（其实错误和D E差不多）
A可以把 ,as there are (legal limits) for c & d, 当成一个状语的插入语，语法上其实没有问题

BDE里边unlike的比较对象不对等，排除；C里边which的用法错误，排除。

the sentence is stating a contrast: condition X is true for cod and haddock, but false for monkfish.
here's another example, similarly constructed:
[i]There is no snow in Los Angeles, as there is in more northern locations.
there be句型的平行要补出there be。

BDE 的 unlike 与比较对象都不对等，排除；
剩下AC，C选项的which一出来，先行词是monkfish，也就是monkfish contributes to its depletion through overfishing.不符逻辑，排除；

只剩下A了，但A 真的要多读几次才顺畅···

1.平行，unlike只能对比名词，但是BDE的limits是不可比的。BDE错。
2.逻辑推理，C的which只能修饰前面的名词fish,但是这样句意就错了，C错。代词which不能指代一件事
3.修饰词，D的being用法错误,D错
4.简洁，becase they are...不如其他表达简洁。BE不好。

he sentence is stating a contrast: condition X is true for cod and haddock, but false for monkfish.
here's another example, similarly constructed:
[i]There is no snow in Los Angeles, as there is in more northern locations.
there be句型的平行要补出there be。
b比较 there be限制比较 鱼

BDE unlike的比较对象不对等
C whcih 不能指代句子

E. Unlike比较双方不可比；前面there be句型是主系表结构，所以后面contributing不能表示伴随结构，而是作为形容词修饰前面的名词catching monkfish；用because引导的原因状语从句来表示方式太过于累赘。

C which不能修饰整个句子，只能修饰monkfish，语义上也不正确

C选项 monkfish前面没加冠词，要用复数
2. 关于monkfish, fish的单复数识别：
if "fish" is singular, it must be used WITH AN ARTICLE ("a", "the", etc.)
i saw a fish swimming beneath me --> singular (1 fish)
i saw fish swimming beneath me --> plural (multiple fish)

1.COMMA + ABSTRACT NOUN is allowed to stand for the ENTIRE IDEA OF THE PRECEDING CLAUSE.
Comma+抽象名词 是用来解释说明前面句子的，是同位语独立主格结构

句子中 as there are for cod and haddock是插入语，
主干是There are no legallimits on the size of monkfish that can becaught。
1、 a circumstance 是同位语。

句子中 as there are for cod and haddock是插入语，
主干是There are no legallimits on the size of monkfish that can becaught。
1、 a circumstance 是同位语。
2、 B、E里面都已经有contribute to 了。导致什么什么。用because有点多此一举了吧。而且B里面有being，这个GMAT中几乎全错，除了偶尔偶尔的几道对。

a的their不是那么清楚，但其他更不能选了

感谢由 kisenana 对此题目的解答所做出的贡献。
选项A There are no legal limits on the size of monkfish that can be caught，a circumstance that contributes to their depletion through overfishing.正确

选项B unlike前后比较对象应一致,There are no legal limits on the size of monkfish that can be caught 和cod or haddock不一致

选项C which不能指代整个句子

选项D UNLIKE 比较对象不一致，which指代错误；

选项E their,they指代歧义；不简洁

不要找对的只找错的
B limits 和cod 不能比 绝对错
C which 指代了monkfish 语义不对绝对错
DE unlike,...,后面没有说对比的对象 一定错
虽然A很别扭但是A没有什么绝对错的地方

unlike平行结构

BDE unlike用法不对
C 选的话which contributes成了修饰monkfish了 也不对

第一遍读A选项应读清成分。