语法大全有几道题不懂

jeans2011

701.The brain is something of a stimulus reduction system, a means to reduce, in order to comprehend, the nearly infinite amount of stimuli that reach the senses at any given moment.
(A) a means to reduce, in order to comprehend, the nearly infinite amount
(B) a means to reduce, in order to comprehend, the nearly infinite number
(C) the means of reducing for comprehending the nearly infinite number
(D) the means that reduces, in order to comprehend, the nearly infinite amount（B）
(E) the means for reducing in order to comprehend the nearly infinite amount
这里划线部分是修饰the brain, 还是修饰a stimulus reduction system？为什么不能用the means to...？
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.
(A) numbers of ospreys, whose huge nests
(B) numbers of ospreys, their huge nests
(C) amounts of ospreys, the huge nests of which
(D) nests of ospreys they（A）
(E) numbers of ospreys, and their huge nests
large amounts of 和large numbers of 有什么区别吗？C项错在哪儿了？

718.The complex tax dispute between the Covered Bridge Mall and Harris Township is not likely to be adjudicated for several years, and, in the meantime, both sides are intent on creating difficulties for the other.
(A) both sides are intent on creating difficulties for the other
(B) both sides are intent on creating difficulties for each other
(C) each side is intent on creating difficulties for the other
(D) each side is intent on creating difficulties for one another（C）
(E) the sides are both intent on creating difficulties for each other
这里能不能用both sides? 如果能的话后面应该怎么说？我是说for the other那部分

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.
(A) numbers of ospreys, whose huge nests
(B) numbers of ospreys, their huge nests
(C) amounts of ospreys, the huge nests of which
(D) nests of ospreys they（A）
(E) numbers of ospreys, and their huge nests
large amounts of 和large numbers of 有什么区别吗？C项错在哪儿了？

718.The complex tax dispute between the Covered Bridge Mall and Harris Township is not likely to be adjudicated for several years, and, in the meantime, both sides are intent on creating difficulties for the other.
(A) both sides are intent on creating difficulties for the other
(B) both sides are intent on creating difficulties for each other
(C) each side is intent on creating difficulties for the other
(D) each side is intent on creating difficulties for one another（C）
(E) the sides are both intent on creating difficulties for each other
这里能不能用both sides? 如果能的话后面应该怎么说？我是说for the other那部分