[填空题]
The Moon orbits the Earth such that the same side always faces d*dbp+,sm 8k 0 dkl8xnthe Earth. Df+3tvhv jqgwb .;j. 2*qtixg7etermine the ratio of the Moon’s spin angular momentum (about its own axis) to its orbital angular momentum. (In tb7vqqxt;gg 2j *jv .i+hft.w3he latter case, treat the Moon as a particle orbiting the Earth.) $\times10^{ -6}$