When the refrigeration demand is small,()
A. the expansion valve will move toward the wide open position
B. the expansion valve will move toward the closing position
C. the feeler bulb will conveys the high temperature
D. the superheat degree will raise
查看答案
采煤工作面要有防止采煤机割煤引燃瓦斯的措施,工作面后20m及有构造地点割煤,必须向滚筒和煤壁喷雾洒水。
A. 正确
B. 错误