— So you were in the supermarket _____ you heard a strange sound, right?

— That's true. I ran out as quickly as possible. [ ]

A. when

B. while

C. then

D. which

表面活性剂

A．可以降低混悬液中微粒的沉降速度
B．可以增加难溶药物在水中的溶解度
C．可以提高溶胶的稳定性
D．可以加速乳剂的乳析
E．可以阻碍混悬液中微粒发生碰撞聚集