如果要切换到oracle用户下用下列哪条语句（）。 A.su - oracle B.

Read and complete.

1.           is she going to there? By train or by bus?

2. I b          some presents on my holiday.

3. Do you like h        ?

4. I'm r         a story book.

5. My friend a          good food on his holiday.

6. I'm going back to C          next month.

7. She likes drawing p____.

8. I often go to s          on foot.

9. I w         to the zoo yesterday.

10. He likes p          football.

区域规划可为城市规划提供( )的重要依据。

A．城市规模

B．城市空间结构和布局

C．城市发展方向和生产力布局

D．基础设施

从用户观点看，引入文件系统的目的是

A．实现虚拟存储

B．保护系统文档

C．保护系统及用户文档

D．实现对文件的按名存取

劳动力供求关系有哪几种类型？各自的表现形式有什么？