等压面、等温面成水平分布状态且层结稳定时，有效位能不等于零。
参考答案：错
To my disappointment, the TV set I had ____ was out of order again. It’s a waste of money.
A．repaired
B．repaired it
C．had repaired it
D．had repaired
当外电源连接，何时厕所镜子荧光灯亮（）？
A.厕所门打开
B.入口为接通
C.天花板灯是明亮
D.应急灯接通
