杀毒软件对于病毒来说永远是落后的，也就是说，只有当一种病毒出现后，才能产生针对这种病

你知道下面的文字在描述哪个人物吗？请把A~E的编号填写在括号内。

小题1:He developed the BASIC language for the first microcomputer and improved the software to make it easier for people to use computers.

小题2:During his lifetime, he had over 1000 inventions, most of which changed the world.

小题3:He is a great thinker. Many Chinese people are still influenced by his thoughts today.

小题4: He was a doctor. In 1938 he came to China from Canada to help the Chinese and died the next year after he operated on a Chinese wounded soldier.

小题5:He is one of the Chinese famous persons. He is the first astronaut who flew into space in China. We are proud of him!

将冰棍从冰箱的冷冻室取出，放进不锈钢茶杯，过一会儿，茶杯的外壁逐渐形成一些小水珠，请问这些水珠是怎样形成的？这个过程是吸热还是放热？

在“学生-选课-课程”数据库中的3个关系如下：
S(S#，SNAME，SEX，AGE)，SC(S#，C#，GRADE)，C(C#，CNAME，TEACHER)
查找选修“数据库技术”这门课程的学生的学生名和成绩。若使用连接查询的SQL语句是：
SELECTSNAME，GRADEFROMS，SC，CWHERECNAME：“数据库技术"ANDS．S#=SC．S#AND 【6】

下列哪些类型的免疫球蛋白不是以单体的形式存在（）。

A.IgE

B.IgG

C.SIgA

D.IgM

E.C+D

什么叫防毒面具？