根据括号内所给中文写出正确的单词。

1. All my classmates in this school are very _____. (有礼貌的)

2. We have a computer lesson on _____ morning. (星期四)

3. The tall boy over there is good at _____. (游泳)

4. Do you often have dinner at your _____ home at the weekend? (祖父母)

5. There are _____ boys in my class. (二十)

下列选项中，视图不能够完成的是

A．指定可更新的表

B．指定可更新的字段

C．检查更新合法性

D．删除和视图相关联的表