Mary seldom put the books back on the shelf in the reading room,---?A,didn't she B,did she
问题描述：
Mary seldom put the books back on the shelf in the reading room,---?A,didn't she B,did she
C,doesn't she
D.does she答案是B感觉好像是D
答
B 是正确的.
seldom 构成否定句,所以是前否后肯,排除A,C .
主语Mary 是第三人称单数,所以put 不可能是原形,只能是过去式,排除D.