罗盘仪用于测定直线的（）
A.真方位角
B.磁方位角
C.坐标方位角
D.象限角
参考答案：B
—I'm sorry to interrupt you, but I don't follow you now.
—Sorry, I _____ it clear about my plan.
A．didn't make
B．hadn't make
C．wasn't making
D．haven't made
灌溉水利用系数
