2000 years ago people already knew it moved around the earth and where it would be in the sky at di
问题描述：
2000 years ago people already knew it moved around the earth and where it would be in the sky at di
2000 years ago people already knew it (moved) around the earth.
为什么不用was moving?
答
was moving是过去进行时即正在进行的动作,
而move 这一动作是people alread knew(人们已经知道）的,是已经完成的,就是动作完成了.
（我的能力有限只能这样解释了）