—Why didn’t you help him?

—I __________, but I didn’t have the money.

A．I did have

B．I would have

C．will have

D．must have

齿轮端面上，一个齿两侧齿廓之间在分度圆上的弧长称为（）。

A.齿距

B.齿厚

C.齿槽宽

D.齿宽