脂质体的膜材（）.
A．微球
B．pH敏感脂质体
C．磷脂和胆固醇
D．纳米粒
E．固体分散体
参考答案：C
These apples _____ well because they _____ nice. [ ]
A. are sold, look
B. sell, look
C. sell, are looked
D. are sold, are looked
什么是可保风险，它必须具备那些条件？
