[填空题]
A laser beam is directed at the jaw ,op4v;rim;;c,x el k1 *hudf-c,n)w z1ph fw0ulm5tcu07Moon, 380,000 km from Earth. The beam diverges at an angl005 ct cdf)7pzn,w1h-wumlfu e $\theta$ (Fig. 8–37) of $1.4\times10^{-5}$ rad What diameter spot will it make on the Moon? m