新prep211求助 thereby副词，不能连接两个句子

Many entomologists say that campaigns to eradicate the fire ant in the United States have failed because the chemicals that were used were effective only in wiping out the ant’s natural enemies, which made it easier for them to spread.

A.       which made[CH1]  it easier for them

B.       which makes it easier for it

C.       thus making it easier for them[CH2]  

D.       thus making it easier for the ant

E.        thereby,[CH3]  it was made easier for the ant

各选项中make后面的it 是形式主语

A、B，which就近指代enemies错

C，them指代不清

D is the best

E，thereby是副词，不能连接两个句子

又是一个分词做结果状语的情况。

是不是原来thus是因为本来句子就需要连接词所以都加上and；

thus只是个副词？

谢谢版主，那关于thereby的用法，有何说法啊？

这里我给出有一题出现thereby错，不能引导句子的例子，在旧的prep里

125[番茄花园1] . (31123-!-item-!-188;#058&006046)

Ranked among great mathematical scientists such as Archimedes, Kepler, and Newton, Abu Ali

al-Hasan ibn al-Haytham, who was born in Iraq in 965 C.E., had experimented extensively with light

and vision, laying the foundation for modern optics and also the notion of science being based on

experiment as well as on philosophical arguments.     

(A) al-Haytham, who was born in Iraq in 965 C.E., had experimented extensively with light and

vision, laying the foundation for modern optics and also the notion of science being based on

experiment as well as

(B) al-Haytham, born in Iraq in 965 C.E., experimented extensively with light and vision, laying the

foundation for modern optics and for the notion that science should be based on experiment as well

as

(C) al-Haytham, born in Iraq in 965 C.E. and who experimented extensively with light and vision,

thereby laid the foundation for modern optics and also for the notion that science should be based

on not only experiment but also

(D) al-Haytham was born in Iraq in 965 C.E. and had experimented extensively with light and vision,

laying the foundation for modern optics and for the notion that science should be based on not only

experiment but also

(E) al-Haytham was born in Iraq in 965 C.E., experimenting extensively with light and vision and

laying the foundation for modern optics and for the notion of science being based on experiment as

well as

A.       过去完成时态had experimented使用错误；the notion of的用法不如the notion that的用法精确。

B.       正确。

C.
            句子没有谓语；thereby是副词，不能连接句子；who experimented, thereby laid中间缺连词；

not only…but also与介词搭配的用法错误。可以是on not only x but also y,  或者not only on x but

also on y。