[填空题]
Eclipses happen on Eart/qa/0 efdx c*ln/-d97w itd udh because of an amazing coincidence. Calculate, us11wcl .tonk7s:cyy c/ing the information inside the Front Cover, the angular diameters (in radians) of the Sun yy/wk 1n 7cc:csot.1l and the Moon, as seen on Earth. Sun = $rad$ Moon = $rad$