瓦斯在煤层中的存在状态为几种()。
A.5种
B.4种
C.3种
D.2种
参考答案:D
Which of the following health-promoting activities should the nurse teach the client with a new laryngectomy
A. Cleanse the mouth three times a day.B. Avoid taking tub baths.C. Develop an aggressive program of exercise to increase airway functioning.D. Dehumidify the air for comfort.
黑神散3功效与作用