You need to brush your after .A. tooth eatB. teeth eatingC. tooth eatingD. teeth eat

问题补充：

You need to brush your after .

A. tooth eat

B. teeth eating

C. tooth eating

D. teeth eat

答案：

A. tooth eat

(答案→)B. teeth eating

C. tooth eating

D. teeth eat

解析：句意:你需要在吃饭之后刷牙。brush teeth 刷牙，teeth 是tooth 的复数形式，根据句意可知，刷牙中的牙齿应该是复数的形式，故可排除A和C；after 在…之后，后面跟动词的ing形式。故选B。