[填空题]
A laser beam is directed at the Moon, 380,000 km from jvrrw3)w:; b9u bjx w69 3 -x bv+qsp6ak(kvemEarth. The beam diverges at an ang -vv 3a(e mxq9kb6+skple $\theta$ (Fig. 8–37) of $1.4\times10^{-5}$ rad What diameter spot will it make on the Moon? m