verbal review 2nd 2. Some bat caves, like honeybee hives, have residents

lynnen

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




我选了D 但是答案是B。   verbal review 的解释是   defending acting sounding scouting  平行  但是有两个 and?? 违背了 A,B,C and D??


但是GMATclub论坛上的解释是    acting and sounding 修饰前面整个take on different duties such as defending the entrance ..........


可是用D来修饰不会更不容易引起误会么


还是说  默认在这种情况下  违背 A,B,C and D 是可以的？？？？

chaserW

做这题时我也认为defending是和scouting平行的
而act和sound通过变为v-ing或to do形式来修饰defending，表示具体怎么defend

看起来act和sound用to do的形式更加不容易让人看起来是和其他两个动词平行，所以一开始我也选了D

看答案后又想了下，to do作为modifier是表示目的的，在这里不合适
因为act和sound表达的更多是一种方式，如何去defendv-ing作修饰可以表示伴随，在这里用的话说得通