Consumers may not think of household cleaning products to be hazardous substances, but many of them can be harmful to health, especially if they are used improperly.

(D) A consumer may not think of household cleaning products as

(E) Household cleaning products may not be thought of, by consumers, as

该题目的主要考点是：think of x as y，这点无争议；问题是，正确答案选了D，对于E的解释是：Passive-voice construction is awkward and wordy. 但在这道题里，后面两个分句的代词them,they都在指代household cleaning products，第一个分句用household cleaning products作主语怎么会awkward呢？个人觉得E反而比D更流畅，难道被动语态就必然错？……烦请高手指点迷津，多谢啦！！ 

被动语态不一定错，og里有几道题都是被动语态的才是正确答案，要看题目的环境以及优选项。

我觉得这道题解题一是如果动作的施动者出现，能够用主动表达清楚简洁的话，是优于被动的

二是如果是最后一个，后半个分句的they or them可以指代customers,会造成指代不清。

d之所以引用a customer就是为了防止后面的指代不清。

 造成后面的指代不清  同意

但感觉还是有点玄 一开始我也选了E

另外还有一点供参考:

longman上关于think的一个词条: be thought to be (doing) sth.意思是 be believed

to be (doing) something.

e.g. Fraud is thought to be costing software companies millions of dollars a

year.
根据这一点, 如果本题一定要用被动来讲的话,是不是说成这样再好一些?
Household cleaning products may not be thought, by consumers, to be

借此地想问一下: 这里的consumers和a consumer是否都是泛指? 单从这一角度上,

二者是否可以互换?