已知等腰三角形有一个内角为80°，则另两个的内角为（ ）。
80°，20°或50°，50°
— You didn't expect to see us, did you?
— _____. [ ]
A. No, I don't know you were coming today
B. Yes, I hadn't known you were coming today
C. No, I didn't know you were coming today
D. Yes, I won't know you were coming today
3M-21型和3M-13型两种气化炉的主要区别是什么？
