使用含重碳酸盐较多的水作为冷却水，当它通过换热器传热表面时，会受热分解产生（）垢。
A、硫酸钙
B、硅酸钙
C、碳酸钙
D、磷酸钙
参考答案：C
These reference books donated by a non-profitable organization are available for ____ wants to have it.
A．anyone
B．someone
C．who
D．whoever
醋炙后，可增强的作用是
A．活血通络
B．润肺止咳
C．活血止痛
D．降逆止呕
E．滋润降火
