[填空题]
The Moon orbits the Ead+c +u y(e:djorth such that the sadahhu :9jf4 b.me side always faces the Earth. Determine th hdu9h:f.jab4e ratio of the Moon’s spin angular momentum (about its own axis) to its orbital angular momentum. (In the latter case, treat the Moon as a particle orbiting the Earth.) $\times10^{ -6}$