GWD5-Q17求助求助！！

dadaowuxing

Q17:
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
D.    There were concerns about public health leading to the construction between 1876 and 1904 of three separate sewer systems serving
E.    There were concerns leading between 1876 and 1904 to the construction of three separate sewer systems for serving
答案是A  为什么B 不对啊~ 求大神啊

annieview

就是一个平白的叙述，没看出哪里需要使用现在完成时，即使要用也用过去完成时。其实一般过去时已经够漂亮了。

dadaowuxing

多谢~

victoria_cc

between 1876 and 1904放在three separate sewer systems方面修饰的

就是3 sss了，但修饰的应该是instruction

polaris16251

between 1875 and 1904 就是过去的一个时间段，跟现在也没关系啊，所以不需要用现在完成时。