工程定额计价制度改革第二阶段的核心问题是( )。
A．量价分离
B．国家指导定价
C．国家定价
D．工程造价计价方式的改革
参考答案：D
.--Where is your father?
--He ________to Shanghai. He has ________ Pudong since last Friday.
A．is going, gone to
B．has gone, been in
C．has been, been in
D．has gone, been to
已知数列{an}是等差数列，若a3+a11=24，a4=3，则{an}的公差是（ ）
A．1
B．3
C．5
D．6
