[求助]XDF-Sec19-10

XDF SC Section 19 Q10:

Question: The data collected by weather airplanes that fly into the heart of the hurricane are useful mainly for gauging the storm's structure and strengh, not for the speed and the path of their movement.

(b) not for the speed and path of its movement

(c) not the speed and path of its movement.

The answer is C. Why is (b) incorrect? Isn't it about parallel strucuture (i.e: for ..., for ...)?

Thanks for any input!

试比较下述三种结构：

are useful mainly for gauging the storm's structure and strengh, not for the speed and path of its movement (B)

are useful mainly for gauging the storm's structure and strengh, not for gauging the speed and path of its movement.

are useful mainly for gauging the storm's structure and strengh, not the speed and path of its movement.

上例可见，B的平行结构不完整。另外be useful for doing是个完整结构。

平行结构需要连词，为什么这里没有连词?

do A, not B  (not不是连词)

not do A but B 可以(A,B用but并列)

我觉得，do A , not B ，not 本身就起到了连词的作用，

本题中，要注意到，the speed and path 是和the storm's structure and strengh是一类的，都是storm的表征，因此，c选项完整的表述是 not for gauging the speed and path of its movement，荧光笔标出的是省略的部分，因此c 对