同程式系统可解决竖向热力失调的问题。
参考答案：错
（）又称闭路阀，作用是接通或截断管路中的介质。
A、截止阀
B、调节阀
C、安全阀
D、止回阀
Mike always says "Hello" to everyone he knows. He is very ______, I think. [ ]
A. helpful
B. funny
C. hard-working
D. polite
