皮皮学，免费搜题
登录
搜题
【单选题】
数据库中，数据模型分为概念模型和逻辑模型，逻辑模型的三个要素分别是（ ）。A.
实体完整性、参照完整性、用户自定义完整性
B.
数据结构、数据操作、完整性约束
C.
数据增加、数据修改、数据查询
D.
外模式、模式、内模式
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【简答题】阅读理解。 May 29th. Dear Jenny, I'm sorry you're ill(病) at home and can't come to school this week, let me tell you what you have on Monday next week. We have math at 8:00. It's boring, I think! Then we h...
【简答题】给问句选择相应的答语。 ( ) 1. Where are you from? ( ) 2. Where are you? ( ) 3. What do you see? A. I see r-o-s-e, rose. B. I'm from China. C. I'm in the house.
【简答题】连词成句。 1. a Wait minute 2. am teacher I a 3. to meet Nice you 4. from I am America
【简答题】I could hardly keep from _____(laugh) when he slipped and fell.2. I'd like to see you _____(come)1. I could hardly keep from _____(laugh) when he slipped and fell. 2. I'd like to see you _____(come) b...
【简答题】Dear Jenny, I’m sorry you ’ re sick and can't come to school this week. Let me tell you what you have on Monday next week. We have math at 8: 00. How boring! Then we have English. That? s interesting....
相关题目：
参考解析：
知识点：
题目纠错 0
发布
