A．α＞β        B．α=β    C．α+β=90°  D．α+β=180°

    A．α＞β            B．α=β              C．α+β=90°          D．α+β=180°

A.α＞β                         B.α=β                           C.α+β=90°                   D.α+β=180°

从A处望B处的仰角为α，从B处望A处的俯角为β，则α、β的关系为

1. A.
   α＞β
2. B.
   α+β＝90°
3. C.
   α＝β
4. D.
   α+β＝180°