关于OG2nd语文分册上的一题语法题 有问题求教

luohenqianqian

语文分册语法第二题
Some bat cave ,like honeybee hives,have residents that take on different duties such as defending the entrance,acting as sentinels and to sound a warning at the approach of danger,and scouting outside the cave foe new food and roosting sites.

A) acting as sentinels and to sound
B) acting as sentinels and sounding
C) to act as sentinels and sound
D) to act as sentinels and to sound
E) to act as a sentinel sounding


答案按照平行选B，我老是觉得acting as sentinels and sounding a warning 是包含在defending the entrance里的，选了C，另外，如果不是包含在里面的作为并列，acting as sentinels and sounding a warning 是单独作为一项与另外两个（即defending the entrance 与scouting outside the cave for new food and roosting sites）平行的吗，否则如何解释这里有两个and呢？

希望NN们帮助解答，不胜感激~

acerjeff

排除法最快。别无他选。

stellapass

语文分册语法第二题
Some bat cave ,like honeybee hives,have residents that take on different duties such as defending the entrance,acting as sentinels and to sound a warning at the approach of danger,and scouting outside the cave foe new food and roosting sites.

A) acting as sentinels and to sound
B) acting as sentinels and sounding
C) to act as sentinels and sound
D) to act as sentinels and to sound
E) to act as a sentinel sounding


答案按照平行选B，我老是觉得acting as sentinels and sounding a warning 是包含在defending the entrance里的，选了C，另外，如果不是包含在里面的作为并列，acting as sentinels and sounding a warning 是单独作为一项与另外两个（即defending the entrance 与scouting outside the cave for new food and roosting sites）平行的吗，否则如何解释这里有两个and呢？

希望NN们帮助解答，不胜感激~

-- by 会员 luohenqianqian (2011/9/5 18:47:49)

这句话的结构是some bat cave, like...such as defending the entrance,....,and scouting outside the cave foe new food and roosting sites.
defending the entrance和scouting...是其具有不同职责的两个列举，而acting as...是修饰前面defending the entrance的，这个题目高清究竟谁和谁平行是关键~

luohenqianqian

我晕，为什么木有人回啊，我没有说清楚么