局麻药的麻醉效能主要决定于()
A．pKa(离解常数)
B．相对分子质量
C．浓度
D．脂溶性(分配系数)
E．蛋白结合
参考答案：D
He has two sons, _____ work as chemists. [ ]
A. two of whom
B. both of whom
C. both of which
D. all of whom
下列哪项不是脏躁的表现
A．情绪低落
B．腰膝酸软
C．呵欠频作
D．精神抑郁
E．哭笑无常
