[填空题]
Eclipses happen on Earth becz371d bpznc3aog /4r; (p pszzau7*by puixh,m9gx 9w7g se of an amazing coincidence. Calculate, using the information inside the Front Cover, the angular diameters (in radians) of the Sun and the Moon, as upxi y97 7mwxbg ,*9ghseen on Earth. Sun = $rad$ Moon = $rad$