[填空题]
Eclipses happen on Earth becavaiyu)l kuj-/k3y (g. zzch-r8t nvjc,;( aj;use of an amazing coincidence. Calculate, using the information inside the Front Cover, the angular diameters (in radians) of the Sun and th,tazc;z;j(r j n-cv8 he Moon, as seen on Earth. Sun = $rad$ Moon = $rad$