常用的表示药物安全性的参数是
A．半数致死量
B．半数有效量
C．治疗指数
D．最小有效量
E．极量
参考答案：C
—How you've changed! You _____ very short.
—But I am not sure if I am taller than you now. [ ]
A. are sure to be
B. use to be
C. are
D. used to be
