工程造价计价主要方法有（）
A、定额单价法一种
B、直接费单价法一种
C、直接费单价和综合单价法两种
D、定额单价法和直接费单价法两种
参考答案：C
The mathematician Bruno was burned at the stake by the Church largely for supporting Copernicus'
theory, yet, a couple of centuries later, Copemican__________seemed harmless. [ ]
A. speakers
B. advocates
C. writers
D. theorists
B．必须使信号产生电谐振
C．必须把传输信号加到高频电流上
D．必须使用开放回路
