---I am afraid that I have to trouble you with this question.

---___________.

A．No,you cannot

B．Go ahead

C．Not at all

D．I don’t mind

把圆柱的侧面沿着它的一条高展开，可以得到一个______或______，它的长是圆柱的______，宽是圆柱的______，因为长方形面积=长×宽，所以圆柱的侧面积等于______．