The following question is about gravitation:
圖片參考:http://i256.photobucket.com/albums/hh172/hkchelsea_united/AL_PHY_100703.png
Thank you very much!
收錄日期: 2021-04-13 17:20:49
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100703000051KK01491