A:四十箱玻璃由株洲运往炎陵﹣铁路
B:2万吨铁矿石由武汉运往上海﹣水运
C:一箱急救药由长沙运往拉萨﹣公路
D:5万立方米天然气由四川运往湖南﹣河运
长方形的面积=____×____,正方形的面积=____×____。
The students often make a lot of ____ (noisy) when the teacher isn't in the classroom.