请教OG中第3题

sue2006

3.       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

谁能给我把这道题的句子结构写一下，根据解释，defending….,acting…..and sounding是平行结构，那么后面的

and scouting……and roosting和这些分词是什么关系？

 

[此贴子已经被作者于2006-8-8 12:50:24编辑过]

chnp

acting…..and sounding是个小平列，defending、acting、and scouting是大平列。大小并列都应该平行。

robinst

补充: new food and roosting sites 也是个小并列. roosting 修饰 sites.