用复凝聚法，以明胶-阿拉伯胶为囊材制备微囊时一般应调节pH值为（）
A.4～9
B.4～6
C.4～7
D.4～8
E.4～4.5
参考答案：E
-_____ do you like summer?
-Because I can swim. [ ]
A. Which
B. What
C. Why
永保无疆之休
