静脉注射某药，X₀＝60mg，若初始血药浓度为15μg/ml，其表观分布容积是( )。

A．4L

B．15L

C．20L

D．4ml

E．60L

In the relatively calm area near the hurricane center，the seas are（）.

A.moderate but easily navigated

B.calm

C.mountainous and confused

D.mountainous but fairly regular as far as direction is concerned