OG 语文 SC 第2题 对答案解释有点疑惑

zcstc007

Some bat caves,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 for 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

官方解释是说 defending, acting, sounding, scouting,平行结构
我觉得应该是defending 和scouting是平行结构， acting 和sounding平行并且是作为修饰defending the entrance用的。 如果四个item一起平行的话那么acting 和sounding之间是不需要and的。

PS： 这样发帖问的话会有人回答了不。。。。。之前发了一次被鄙视了。。。。。

zcstc007

补充一句  正确答案选B

kiwifoodtown

列举的一般形式是，Ving, Ving and Ving. 如果还有第四项就再加 and Ving.

zcstc007

列举的一般形式是，Ving, Ving and Ving. 如果还有第四项就再加 and Ving.

-- by 会员 kiwifoodtown (2012/12/3 14:14:24)

我记得manhattan上的说法式只有最后一个加AND的啊

kiwifoodtown

列举的一般形式是，Ving, Ving and Ving. 如果还有第四项就再加 and Ving.

-- by 会员 kiwifoodtown (2012/12/3 14:14:24)

我记得manhattan上的说法式只有最后一个加AND的啊

-- by 会员 zcstc007 (2012/12/5 22:01:21)

我的说法也不对，但我觉得这题的主要目的就是考你对平行的辨识，只要会了你就对了，何必要追究几个平行，加哪个介词这种牛角尖呢？