A means a holiday, and people can do whatever they like during the holiday.
A:seat
B:vacation
C:festival
下列各项具有社会行为的动物是 ()
如图所示,光滑圆弧的半径为80cm,一质量为1.0kg的物体由A处从静止开始下滑到B点,然后又沿水平面前进3m,到达C点停止.g取10m/s2,求:
读北半球大气环流示意图,回答: