The sun is not a point so that all sunlight are paralle to each other
所有跟贴·加跟贴·新语丝读书论坛http://www.xys.org/cgi-bin/mainpage.pl
送交者: HunHunSheng 于 2005-1-12, 17:28:03:
回答: 他是先假设地球是圆的,再假设太阳是无穷远的. 由 wangle 于 2005-1-12, 17:25:38:
所有跟贴:
加跟贴
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