To improve the quality of our products, we asked for suggestions had used the products.
A. whoever
B. who
C. whichever
D. which
网友回答
(答案→)A. whoever
B. who
C. whichever
D. which
解析：句意：为了提高我们产品的质量，我们征求了用过的人的建议。这里是宾语从句，ask sb for suggestions,这里缺sb,就用代词whoever来代替。ask sb for suggestiongs是动词词组在整个句子中，who侧重于指事情，whoever=anyone who侧重于指人，故选A。