中华人民共和国电力法》：国家提倡电力（）与电网、电网与电网并网运行。
A.生产企业
B.用户
C.建设单位
D.以上均不正确
参考答案：A
单桩竖向承载力特征值其中安全系数K等于（）。
A．1.3
B．2
C．1.2
D．1.6
What can we infer from the passage
A．The temple has a long history.
B．The renovation of the temple was easy with modem technology.
C．The bricks in the temple are not so valuable as those in the Forbidden city.
D．The renovation was done according to the orders of Emperor Qianlon
其中安全系数K等于（）。