If anyone happens to drop in while I am out, _____ him or her leave a message. [ ]

A. tell

B. ask

C. get

D. have

拉伸时，塔柱链条要怎样处理（）

A、所有链节呈一条线

B、链条在塔柱顶杆锁紧窝锁紧

C、链条尾部拴在导向环手轮上

D、要使用规定的链条