径流系数
参考答案：
径流量与降雨量的比值称径流系数，其值常小于1。
With their market share shrinking, analysts ______ that their profits have fallen by around 15%.
A．accomplish
B．reckon
C．promote
D．urge
退行性骨关节病主要的病变部位是（）
A.关节软骨
B.骨皮质
C.关节韧带
D.滑膜组织
E.骨膜
