求助两道prep语法题

starry1007

考试临近了，发到语法版却没人回复，只好发来这里啦~~两道Prep语法题

1.The parachutelike membranes of Africa's scaly-tailed flying squirrels differ from those of the flying squirrels in the family Sciuridae because they are attached to a cartilage rod at the elbow instead of the wrist.      

(A) because they are attached to a cartilage rod at the elbow instead of
(B) because of being attached to a cartilage rod at the elbow rather than at
(C) in their attachment to a cartilage rod at the elbow instead of being attached at
(D) in that they are attached to a cartilage rod at the elbow rather than at
(E) in their being attached to a cartilage rod at the elbow instead of

A.     缺少介词at，比较存在歧义。
B. Because of being表达笨拙。
C. in their attachment to和being attached at形式不对称；being attached at the wrist改变句子愿意：
membranes是被附着在位于腕处的软骨棒上，而不是被直接附着在腕上
D.    正确，此句是两个介宾结构――at the elbow和at the wrist比较，第二个介词at不能省略，否则造成歧义。可能为：attached to a cartilage rod instead of (to) the wrist，wrist和rod平行，也可能为：cartilage rod at the elbow instead of (at) the wrist，wrist和elbow平行。根据句意可知，只有后者才是正确答案。
E.     缺少介词at，比较存在歧义

为何我觉得D中they指代对象是flying squirrels，从而指代错误？


2.Although the turtle has been toothless for more than 150 million years, in some contemporary turtle species the moderately sharp and jagged edges of their horny jaws function for teeth.    
(D) the horny jaws function as teeth do
(E) the horny jaws function as teeth
答案选E而不是D，说D里面function习语错误，为什么，function不是动词吗，为什么要省略do呢？

黄宋菠菜

楼主最好把下划线画出来

sweetming

本人愚见：第一题they指代主语“The parachutelike membranes ”
                第二题中teeth是和the horny jaws比较，而不是强调function这个动作的相似性

黄宋菠菜

第一题如果是第三人称只带不清的话只有b对了，但是b的错误很明显，那么就不要管指代问题啦。楼主要善于抓住主要问题。而且本人认为英语的习惯性表达中，a differs from b because 。。。。。中because的主语和原主语一致（即a）这样比较通顺。
第二题中as在这里我觉得是一种典型的as用法。是作为。。。。的意思 不一定对 嘿嘿

starry1007

谢谢ls几位指点，我明白啦~