问题
选择题
— Did you visit Taipei International Flora Expo (台北花博会)?
— Yes. It is the world of flowers. You can see many kinds of flowers in different
_____- red, pink, purple, yellow, black... [ ]
A. sizes
B. names
C. shapes
D. colors
答案
答案：D
d，重力加速度为g．忽略手的运动半径和空气阻力，绳能承受的最大拉力为定值．
，要使绳仍在球运动到最低点时恰好断掉，求小球飞行的水平距离．