Dents are not permitted if they prevent correct operation of the parts.如果压痕妨碍零件的正确操作， 则不允许有压痕。
A.Correct operation of the parts does not allow dents to occur, B.Dents that have an influence on the correct operation of the parts are not allowed. C.Dents can prevent correct operation of the parts, so they are not permitted.正确答案B
