下列词语中不代表旋律进行方向的是（）。
A.水平进行
B.上行
C.中行
D.下行
参考答案：C
解析：旋律进行的方向有水平进行、上行和下行。
---I came to your office yesterday morning, but nobody was in.
--- Sorry, we _______ a meeting .
A．have had
B．are having
C．were having
D．had
画出如图所示拉力F的力臂．
