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关系代数运算是以集合操作为基础的运算，其五种基本运算是并、差、__（1）__、投影和选择，其他运算可由这些运算导出。为了提高数据的操作效率和存储空间的利用率，需要对__（2）__进行分解。

空白（2）处应选择（）

A.内模式

B.视图

C.外模式

D.关系模式

答案

参考答案：D

解析：关系代数运算是以集合操作为基础的运算，其五种基本运算是并、差、笛卡儿积、投影和选择。为了提高数据的操作效率和存储空间的利用率，需要对关系模式进行分解。

阅读理解

短文改错(共10小题；每小题1分，满分10分)

假定英语课上老师要求同桌之间交换修改作文，请你修改你同学写的以下作文。文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏字符号（），并在其下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1、每处错误及其修改均仅限一词；

2、只允许修改10处，多者（从第11处起）不计分。

After watch “English TV” last Sunday morning, I phoned to my classmate and told him to go to see a film in the afternoon. Before the film was over, we returned to school to do our lessons. While we are having a rest in the corridor, I saw Mr Liu, my head teacher. He told me that we had made some progresses in English, but my Chinese lagged behind, especially my Chinese composition. He suggested I must read more and keeping a diary every day. In the evening my father told me that reading newspapers would do me well for improving composition writing. That was really good idea! What they said was quite right, and I should follow their advice.
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单项选择题

下列各项财政支出中，体现政府非市场性分配活动的支出是( )。

A．建设性支

B．转移性支出

C．购买性支

D．消费性支出
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