单选题 At the awards ceremony, Mrs. Shin will present a prize to the employees who have ______ for the company for over 20 years.
A. served
B. engraved
C. approved
D. received

【正确答案】 A

【答案解析】中级问题本题只对所有选项进行词义分析也能解题，但如果从语法入手则能更准确更快速地解答。看到空格后的介词，就知道空格内需要一个不及物动词。engrave(雕刻)和receive是及物动词；approve (of)既可及物也可不及物，但它不和for搭配，而且词义上也不合适。 serve for是正确答案，表示“为……服务”。另外，它也可以像serve a customer这样做及物动词使用。