[填空题]
Eclipses happen on Eart /h1kh *wvo h 15py)s(s8mtxcvh bsd4u1a z h0)jwuedcl u-07op4 ecause of an amazing coincidence. Calculate, using the information inside the Front Cover, the angular diameters (in radians) of the Sun and td -dsu0h)je4 p1zc 4ou7aulw0he Moon, as seen on Earth. Sun = $rad$ Moon = $rad$