过热器减温喷水来至给水泵出口。（）来至给水泵中间抽头。
参考答案：再热器减温喷水
___________ they have some opposite views, they all think Chinese medicine is helpful.
A. Until B. Although C. Since
如图所示，重20N的物体放在粗糙水平面上，用F＝8N的力斜向下推物体。F与水平面成30°角，物体与水平面间的动摩擦因数μ＝0.5，则
A．物体对地面的压力为24N
B．物体所受的摩擦力为12N
C．物体所受的合力为5N
D．物体所受的合力为零
