[填空题]
Eclipses happen on Earth becoz:g z esmn j6v);4k8xav-j6krzp 4 u4f3 rcw9ause of an amazing coincidence. Calculate, using the information inside the Front Cover, the angular diameters (in ra3zv4-a6rpk 9w j4 ufcrdians) of the Sun and the Moon, as seen on Earth. Sun = $rad$ Moon = $rad$