GWD24套第21套几道语法题请大牛再次指点

18. GWD31-Q18

According to a recent survey of municipal services, the city’s streets could be cleaner, its fire code be better enforced, and its crime rate reduced if the current administration improved its management practices.

A.
             be better enforced, and its crime rate reduced

B.      better enforced, and its crime rate reduced  

C.      could be better enforced, and it could reduce its crime rate
        

D.      better enforced, and its crime rate could reduce

E.       could be better enforced, and its crime rate reduce

正确答案: B.     

为什么不是A?

In 1994 the white house named Dr RuthR. Faden chairperson of the federal advisory committee of experts they assigned to do a report on the history and ethics of the government’s radiation experiments on humans in the 1950’s and 1960’s .

A.          they assigned to do

B.          to be assigned doing

C.          that was being assigned doing

D.          assigned for doing

E.          it assigned to do   
                        

正确答案: E

如果是assinged to do对吗? it 在这里不是多余吗? assigned...修饰experts, 不是吗? 请指教!

GWD31-Q18：很老的争议题，A,B,C都有人选
个人比较倾向于A，理由如下：
首先根据句子结构后面的if从句在，前面一定是could引出的三个并列动词，而后面两个could省略；其次因为可以推断出reduced前面有could的省略，则可以推断出reduced前面必有助动词be；再者有be better enforced在，后面的reduced前面的be省略合情合理.
对于B中，助动词与系动词无法并列.
C中it必然是指代city，但是city无法主动地去reduce crime rate.

GWD31-37:be assigned to do是固定搭配所以排除B,C,D.而E里面在it前面省略了that，因为experts在定从里做宾语，而且it的指代也比较清晰。"assigned to do"我同意，直接一个过去分词短语作为(被动)修饰词.

ps：强烈建议一题一贴或者在题目中标注题号.这样可以方便后人查阅