混悬液中羧甲基纤维素钠的作用是（）
A.助溶剂
B.增溶剂
C.防腐剂
D.助悬剂
E.分散剂
参考答案：D
病毒感染的儿童
A．扪诊B．咬诊C．X线检查D．松动度检查E．局部麻醉检查
—Is that ______ volleyball?—Yes. Bill likes playing ______ volleyball. ______ volleyball is his.
A．the; a; /
B．/; the; /
C．/; the; The
D．a; /; The
