如图，有一束光线从空气斜射入某种透明物质中，在界面处发生反射和折射，则____是反射光线，折射角是角____。
OD； ∠1
_____ a reply from Mabel, Jack sent another e-mail to her. [ ]
A. Not receiving
B. Having not received
C. Not received
D. Not having received
采空区处理方法可影响地表移动的距离。
