(2013·辽宁五校第一联合体高三考试)—The ice cream is really delicious. Can I have some more?

—________.

A．Behave yourself

B．Please yourself

C．Do it yourself

D．Be my guest

冷态运行中的循环冷却水为常温，水质未浓缩，对循环水系统和换热设备来说主要问题是结垢。