麻醉药分压在两相中达到平衡时的麻醉药浓度比为（）
A.LD50
B.分配系数
C.ED50
D.T1
E.可靠安全系数
参考答案：B
My son ____ coke , but now he ______ milk.
A．used to drink; is used to drinking
B．used to drinking; drinks
C．used to drink used to drink
D．used to drink; is drinking
Susan is London. She likes bread breakfast. [ ]
A. from ; for
B. to ; to
C. of; for
D. from ; to
