[填空题]
Eclipses happen on Eartpm-l.:vyfbbyx- jo 4 79ioa*k h because of an amazing coi azultm fcw:1. 5h9.vxncidence. Calculate, using the information inside the Front Cover, the angular diameters (in radians) of the Sun and t5 tcl hvawm.z.:19 uxfhe Moon, as seen on Earth. Sun = $rad$ Moon = $rad$