[填空题]
Eclipses happen on Earth becauseyf6v;;a ss r+c of an amazing coincidence. Calculate, 1-mwpb ixd, e4d+ gan8using the information inside the Fr- 81nwd bexa4+, ipgdmont Cover, the angular diameters (in radians) of the Sun and the Moon, as seen on Earth. Sun = $rad$ Moon = $rad$