2005-09-17 15:55:15丁丁&娜娜

Astronomy

哪兩種力量使行星一直在固定的軌道上繞著恆星運行?



答案是


引力(gravity)


慣性(inertia)



Honey , that’s what u need 2 do

rotate around me ,

like plante rotate around fixed star!

and i’m yr fixed star!