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问题 单项选择题

数据库系统的核心是

A．数据库

B．数据库管理系统

C．模拟模型

D．软件工程

答案

参考答案：B

解析： 数据库管理系统(Database Management System，简称DBMS)是数据库的机构，它是一种系统软件，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，数据库管理系统是数据库系统的核心。

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Important Ages in the UK
Age
What you can do
5
You have to go to school.
12
You can buy a pet.
13
You can get a part-time job, but you can’t work for more than two hours on a school day or on Sunday.
14
You can go into a bar, but you can’t buy alcohol(酒).
16
You can leave school.
A boy can join the army with his parents’ permission(许可).
You can drive a motorcycle.
You can have beer or wine with a meal in a restaurant.
17
You can hold a license to drive most small cars.
18
Age of maturity—you have grown up in the eyes of the law.
You can marry even without your parents’ permission.
You can buy and drink alcohol in a bar.
21
You can hold a license to drive a large passenger bus.
You can have a license to sell alcohol.
You can become a member of Parliament(议会).
 
小题1:In Britain, what can you do when you are 14 years old?
A．Buy a pet.B．Join the army.
C．Drive a motorcycle.D．Buy alcohol.
小题2: In Britain, you can start to drink wine in a restaurant at the age of _______.
A．twelveB．fourteenC．sixteenD．eighteen
小题3: The underlined word “maturity” means “_______”.
A．独立B．选举C．执法D．成熟
小题4: Which of the following is not allowed for the 18-year-old teenagers?
A．Leave school.B．Joining the Parliament.
C．Driving small cars.D．Marrying.
小题5:If your 19-year-old friend is going to live in Britain, you should tell him that he can’t _______.
A．drive a motorcycleB．drive a large passenger bus
C．get a part-time jobD．buy alcohol in a bar
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多项选择题

乳剂型气雾剂中可包括

A．润湿剂

B．稳定剂

C．乳化剂

D．抛射剂

E．潜溶剂
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