地心引力不是牛頓發明的概念，古希臘人稱為自然向地心下落的力量，在地球另一邊也成立。
WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.
Copyright ©1998-2025 wenxuecity.com All rights reserved. Privacy Statement & Terms of Use & User Privacy Protection Policy
