制粉系统的通风出力是指()对()的携带能力,单位以()表示。
参考答案:气流;煤粉;m2/h
下列左心衰竭所致呼吸困难的特点不包括()
A.应用强心剂可好转
B.为混合性呼吸困难
C.夜间减轻
D.仰卧加重
E.活动时出现
—Flight CA 581_____________. I must be off now. —Have a nice trip.
A.is being announced
B.has announced
C.was announcing
D.will be announced