单选题 Sales representatives always need to be ______ of the effectiveness and swiftness of their services to their customers, who will share their experiences.

(A) conscious
(B) capable
(C) committed
(D) anxious

【正确答案】 A

【答案解析】要记住“be+形容词+介词”这个固定用法。能和后面的of搭配的是A选项和B选项，接下来就是词义的分析。销售部的职员必须“注重”效率，所以be conscious of是正确答案。be capable of是“能做某事”的意思。