河流的弯曲系数是沿河流（）两点间的实际长度与其（）的比值。
参考答案：中泓线；直线距离
—Father's Day is coming. I'm going back home.to see my father.
—___________. [ ]
A. Give my best wishes to him
B. It's very kind of you
C. Say goodbye to him, please
D. See you soon
麻黄、香薷都能
A．温经通阳B．利水消肿C．温肺止咳D．通窍止痛
