【简答题】阅读理解。 Different countries and different people have different manners (礼貌). We must know their customs (风俗习惯), or they will think we are ill-mannered (不礼貌). If you visit a Chinese family, you should k...
【简答题】We have known for a long time that flowers of different plants open and close at different times of day. This is so 1 that there seems to be no need to ask the reason for it. Yet no one 2 understands ...