肝脏手术后吸氧的主要目的是
A．防止脑缺氧B．防止呼吸道感染C．保护肝脏D．增强抵抗力E．利于手术后恢复
参考答案：C
— Why did the teacher ask for me?
— He wanted you to _________ your absence last night. [ ]
A. call for
B. care for
C. account for
D. pay for
P100代表该波对于规定的参考电极值为正向，正常的潜伏期平均在（）
A.50ms左右
B.100ms左右
C.150ms左右
D.200ms左右
E.10ms左右
