[填空题]
A laser beam is directed at the Mo9kn/rq8nu4 uma s-99tlw 09yzc9qsjvon, 380zm+i t+8kyck0hr-*q i ,000 km from Earth. The beam diverges at an*k-z+ict8 h0y rkqm +i angle $\theta$ (Fig. 8–37) of $1.4\times10^{-5}$ rad What diameter spot will it make on the Moon? m