题目内容：

It's ____ to talk loudly in a reading room.
A.good mannersB.bad manners C.a bad manner D.a good manner
怎么区别有S和无S

优质解答

b
bad manners
词组
如
It's bad manners to talk with a full mouth.
嘴里吃着东西说话是不礼貌的