A. Pasen .

B. Laiman.

C. Banme, trong vùng nhìn thấy. 

D. Banme, trong vùng tử ngoại.

A.  $\frac{1}{{\lambda }_1}=\frac{1}{{\lambda }_{\alpha }}+\frac{1}{{\lambda }_{\beta }}$

B.  ${\lambda }_1={\lambda }_{\alpha }+{\lambda }_{\beta }$

C.  ${\lambda }_1={\lambda }_{\beta }-{\lambda }_{\alpha }$

D.  $\frac{1}{{\lambda }_1}=\frac{1}{{\lambda }_{\beta }}-\frac{1}{{\lambda }_{\alpha }}$

A.  $\frac{1}{{\lambda }_1}=\frac{1}{{\lambda }_{\alpha }}+\frac{1}{{\lambda }_{\beta }}$

B.  ${\lambda }_1={\lambda }_{\alpha }+{\lambda }_{\beta }$

C.  ${\lambda }_1={\lambda }_{\beta }-{\lambda }_{\alpha }$

D.  $\frac{1}{{\lambda }_1}=\frac{1}{{\lambda }_{\beta }}-\frac{1}{{\lambda }_{\alpha }}$

A.  $\frac{1}{{\lambda }_1}=\frac{1}{{\lambda }_{\alpha }}+\frac{1}{{\lambda }_{\beta }}$

B.  $\frac{1}{{\lambda }_1}=\frac{1}{{\lambda }_{\alpha }}-\frac{1}{{\lambda }_{\beta }}$

C.  $\frac{2}{{\lambda }_1}=\frac{1}{{\lambda }_{\alpha }}-\frac{1}{{\lambda }_{\beta }}$

D.  $\frac{2}{{\lambda }_1}=\frac{1}{{\lambda }_{\alpha }}+\frac{1}{{\lambda }_{\beta }}$