[填空题]
The first-order line of 589-nm light falling onyw;6tk-,o3 x lim i0x njwbilbl i2;,8 a diffraction grab i: nim7rot8e ykrn41v+.q9o ting is observed at a 1nv key8mn+ir9 .:1r o7bi4qto5.5$^{\circ}\,$ angle. How far apart are the slits? $\mu m$
At what angle will the third order be observed?
