Rulesareeverywhere.Whenyou’rereadingatthelibrary,playin...
问题详情：Rulesareeverywhere.Whenyou’rereadingatthelibrary,playingbasketballontheplaygroundordrivingontheroad,youwillhavetofollowsomerules.Butdoyouknowaboutanyrulesonaplane?Ifyou’reonaplaneinAmerica,y...