[填空题]
Eclipses happen on Earth because ofz ezztze,xpwc 37a-3 +rr: a4a*q 8*lahfn(6 9ccvtqy an amazing coincidence. Calculate, using the a qct 68y(lcq* fn*hv9information inside the Front Cover, the angular diameters (in radians) of the Sun and the Moon, as seen on Earth.
Sun = $rad$ Moon = $rad$