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问题 单项选择题

数据库系统的核心是

A．数据模型

B．数据库管理系统

C．软件工具

D．数据库

答案

参考答案：B

解析： 数据库管理系统是一种系统软件，负责数据库中的数据组织、数据操纵、数据维护、控制及保护和数据服务等，因此数据库管理系统是数据库系统的核心。

阅读理解

阅读理解。

    Some people think we have too much dirty air in large cities. Some of the dirty air is from cars. The more

cars there are in cities, the more dirty air we will have. Some people think we may go to work by bike,

because no dirty air is from bikes. The more people go to work by bike, the fewer cars there will be in cities.

So the dirty air will not be much. Do you think it is a good idea?

1．Some people think we have ______ in cities. [ ]

A. too much air

B. too much dirty air

C. too much clean air

D. too much dirty water

2．______ the dirty air is from cars. [ ]

A. Most of

B. All of

C. Some of

D. Many of

3．If we go to work ______, there will not be so much dirty air in cities. [ ]

A. by car

B. by bus

C. by air

D. by bike

4．The more cars there are in cities, ______ we will have. [ ]

A. the more clean air

B. the less dirty air

C. the more dirty air

D. the dirty air

5．The writer thinks that we should ______. [ ]

A. don't go to work

B. go to work by bike

C. stay at home

D. go to work by car

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单项选择题

建设项目的全过程管理是指( )所进行的项目管理。

A．建设监理单位从设计阶段到施工阶段

B．业主从项目建议书到竣工投产

C．设计单位从初步设计到施工图设计

D．施工单位从投标报价到竣工验收
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