[填空题]
Light falling normally on5 fh sh/1fk2 mgigcb4kjrm2 dz*g01h*fdpz):-m r-u7ijv6 a ba $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$ nm
$\lambda_{36.4}$ nm
$\lambda_{47.5}$ nm
