[填空题]
Light of wavelength 680 nm falls on two slits and produces an inlat )lnc8yj) ;terfencc+ x/.;bn.ww qlw6a rence pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separwxc qw+ . lc/nnb6;a.wation of the two slits? mm
