[填空题]
Eclipses happen on Ear8) su3c5yx0 sjzkrdu f3 ,nm3ith because of an amazing coincidence. Calculate, ;ie3h lh vfh9, qu:.vuusing the information inside the Front Cover, the angular diameters (in radians) of the Sun h.iu9hlh3;evuf :q,v and the Moon, as seen on Earth. Sun = $rad$ Moon = $rad$