radial function

例句：

1. 1. Thesatellite orbits the earth in aradial path.
   卫星以径向路径绕地球运行。
2. 2. Radial symmetry is acharacteristic of many crystal structures.
   径向对称是许多晶体结构的特征。
3. 3. Theradial growth ofthe tree is due to theabsorption of sunlight.
   树木的径向生长是由于吸收阳光造成的。