大全987-624

1.        Scientists have suggested that once every 10 million years or so a truly colossal object from space cuts through the atmosphere and slams into Earth, sending up a global pall of dust that blots out the Sun, alters the climate, and changes the course of evolution by killing off many plant and animal species.

(A) sending up a global pall of dust that blots

(B) thus sending up a global pall of dust to blot

(C) thereby sending up a global pall of dust to blot

(D) and that sends up a global pall of dust, blotting（A）

(E) which sends up a global pall of dust, blots

请问C 为啥不好？

平行结构，如果用C句的to blot,后面也都需要不定式，to do ,do and do.

这里是does,does and does.

另外thereby表因果，这里原句是伴随状态。所以thereby多余。