单选题 Every knife and fork __________ carefully.
A. have cleaned B. has cleaned
C. have been cleaned D. has been cleaned

【正确答案】 D

【答案解析】主谓一致。knife和fork一起使用，被看作一个整体，它们作主语时谓语动词用单数。因为主谓之间是被动关系，所以用被动语态。