国家按行政建制设立的直辖市、市、（）称城市。
A、县
B、区
C、乡
D、镇
参考答案：D
互为同素异形体的一组物质是
A．氢气与液氢
B．水银与银
C．干冰与冰
D．氧气与臭氧
A client with heart failure loses 3.2 kg while hospitalized. Approximately how many pounds has the client lost()
A. 1 pound.
B. 3 pounds.
C. 5 pounds.
D. 7 pounds.
