[填空题]
Eclipses happen on Earth because of an amazing coincixsll q;+t1),k y)o t2kd2dxg ldence. Calcmdnk)bi t6n,k-gxd+- ulate, using the information inside the Front Cover, the angular diameters (in radians) of the Sun and the Moon, ,)kt- nx k+mg 6-dbindas seen on Earth. Sun = $rad$ Moon = $rad$