[填空题]
The Moon orbits the Earth such that the same si9q hxv a qf5p7exgq- yj3(;a8yde hii 7xnq;+z k:*eq+zf always faces the Earth. Determine the ratio of the Moon’s spin angular momentum (about its own axis) to its orbital angular +:zxf;q knhiz qi7e*+ momentum. (In the latter case, treat the Moon as a particle orbiting the Earth.) $\times10^{ -6}$