[填空题]
A parallel beam of light from a He-Ne laser, with a wat2hg1w;scdvffr 3, z -veleux .9+zjscfb.z 5n c5dngth 656 nm, falls on two very narrow slits 0.0.szbc+9 d5fz .xu5jnc 60 mm apart. How far apart are the fringes in the center of the pattern on a screen 3.6 m away? cm
