[填空题]
Eclipses happen on Earth becau4a +ngc3p pz5(zfs6f ndym -4ase of an amazi :y;z.px+4 nytzpbhi1-s m7ling coincidence. Calculate, using the information inside the Front Cover, the angular diameters (in radians) of the Sun andt mhysz7iyp; z+1 b:inp4xl -. the Moon, as seen on Earth. Sun = $rad$ Moon = $rad$