皮皮学，免费搜题
登录
搜题
【单选题】
数据库系统中最早出现的数据模型、用树形结构表示各类实体以及实体之间的联系的模型是( )。A.
层次数据模型
B.
网状数据模型
C.
关系数据模型
D.
面向对象数据库
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【简答题】Tokyo is one of those places that you can love and hate at the same time. In Tokyo there are always too many people in the places where I want to go. Of course there are too many cars. The Japanese dr...
【简答题】标准公差分为 级。
【简答题】Meb Keflezighi has had a very 1.______________ athletics career since moving to the United States with his family at age 12. His two biggest highlights are a silver medal in the marathon at the 2004 A...
【判断题】1851 年5月11日-10月11日,英国伦敦首次举办了“万国工业博览会”这是第一个发展到国际规模的工业展览会,亦是第一届世界博览会。这次博览会堪称展览会历史上的里程碑。
A.
正确
B.
错误
【单选题】Tokyo is one of those places where you can love and hate at the same time. In Tokyo there are always too many people in the places where I want to be. Of course there are too many cars. The Japanese d...
A.
it has a smaller population
B.
it is an international city
C.
it is more difficult to go somewhere on foot in Tokyo
D.
its people are more friendly and more polite
相关题目：