请教两道语法题，谢谢

春天的花儿会开

1、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.
A. 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.
C. There are legal limits on the size of cod and haddock that can be caught, but not
for monkfish, which contributes to its depletion through overfishing.
the key：C
请教高手这两个选项该如何快速区分。不知道是否有这个there be的比较呢？谢谢
2、Concerns about public health led to the construction between 1876 and 1904 of three separate sewer systems to serve metropolitan Boston.                                       
A. Concerns about public health led to the construction between 1876 and 1904 of
three separate sewer systems to serve
B. Concerns about public health have led to the construction of three separate sewer
systems between 1876 and 1904 to serve
C. Concerns about public health have led between 1876 and 1904 to the construction of three separate sewer systems for serving
the key: A
我的问题：1、between 1876 and 1904为什么不用现在完成时，当时作的时候我选了B
2、between... and...修饰语的位置到底该放到哪里呢？A中这个状语竟然将construction of 给分离了？谢谢

BetterMan

不是高手,一起讨论一下吧.
1)答案是C? which指代的对象呢?
2) 过去的一段时间,可以不用完成时; lead to这个动作在过去就完成了,没有持续到现在.
between的位置该是就近修饰所要修饰的对象比较好吧. 这里是指construction是在这段时间那完成的.不是修饰Lead这个动作.
B中的位置好像在修饰system了;
不很确定,再等NN吧!