下列属于特异性免疫的是 [ ]
A．皮肤的屏障作用
B．吞噬细胞的吞噬作用
C．溶酶体的杀菌作用
D．患过天花的人以后不再患天花
答案：D
连词成句。
1. I, have, card, can, your,library, please (?)
2. can, about, you, find, where, out, England (?)
3. a, bought, computer, Mum, new, yesterday (. )
4. book, there, food, we, a, find, about, can (. )
5. wants, an, she, make, to, Mum, e-card, her, for (. )
存储虚拟化虚拟的对象是（）
A：内存
B：磁盘
C：光纤存储
D：CPU
