gwd-1-24

Q24:

By sucking sap from the young twigs of the hemlock tree, tree growth is retarded by the woolly adelgid, causing needles to change color from deep green to grayish green and to drop prematurely.

A.      tree growth is retarded by the woolly adelgid, causing needles to change color from deep green to grayish green and to drop

B.       tree growth is retarded by the woolly adelgid, and this causes the color of needles to change from deep green to grayish green, and their dropping

C.       the woolly adelgid retards tree growth, which causes needles to change color from deep green to grayish green, and dropping

D.      the woolly adelgid retards tree growth, causing needles to change color from deep green to grayish green and to drop

E.       the woolly adelgid retards tree growth, and this causes the color of needles to change from deep green to grayish green, and the their dropping

C.      why not C??

答案是什么呢？个人感觉是D. cause sb. to do sth., 而且符合平行对称结构

which一般很少指代前边整个句子,所以c不如d好

C有两处错误：

1 which不能指代前面的一句话，只能指代名词（一般就近指代，如果which从句有单复数谓语在没有歧义的情况下可以指代比较远的名词），这里从句意讲应该指代前面的整句，所以不对。

2 后面的and dropping无法解释成分，既不构成平行结构，也不能做分词短语的功能，因为有连词and。

同意！其实，本题从前面可以看出，By sucking ...., 逻辑主语就必须是the woolly adelgid,排除A.B

而E中the their dropping，the 与their两个特指显然是错误的

C中which就近指代名词（除非有单复数提示或逻辑关系表明可以跳跃指代），tree growth causes needles....显然是不符合逻辑的

那么只有D, 分词causing 做结果状语，修饰动词retard

E中的and this causes…，this不能单独一个人出现。裸奔是不对的！

Q24:

By sucking sap from the young twigs of the hemlock tree, tree growth is retarded by the woolly adelgid, causing needles to change color from deep green to grayish green and to drop prematurely.

A. tree growth is retarded by the
woolly adelgid, causing needles to change color from deep green to
grayish green and to drop

D.      the woolly adelgid retards tree growth, causing needles to change color from deep green to grayish green and to drop

我晕啊，我第一下就把A\D给排除了，因为看到causing就觉得肯定不好，会指代不清的。像我这种思维咋办啊！！请NN指教，我的这个第一反应到底什么时候用比较合适呢？？？谢谢了。