肠外营养最严重的技术并发症是()
A.局部出血
B.气胸
C.空气栓塞
D.损伤胸导管
E.臂丛神经损伤
参考答案:C
—Is Jack in the classroom now?
—No, he football on the playground.
A.plays
B.played
C.is playing
D.was playing
越容易失去电子的金属其活泼性越弱。