皮皮学，免费搜题
登录
搜题
【简答题】
商业管理数据库中有 3 个实体集:一是“商店”实体集,属性有商店编号、商店名、地址等;二是“商品”实体集,属性有商品号、商品名、规格、单价等;三是“职工”实体集,属性有职工编号、姓名、性别、业绩等。 商店与商品间存在“销售”联系,每个商店可销售多种商品,每种商品也可放在多个商店销售,每个商店销售一种商品,有月销售量;商店与职工间存在着“聘用”联系,每个商店有许多职工,每个职工只能在一个商店工作,商店聘用职工有聘期和工资。 ( 1 )试画出 E-R 图。 ( 2 )将 E-R 图转换成关系模型,并说明主键和外键。
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】Traveling can be a way to gain life experiences，especially during Spring Break—a week long school vacation in the United States. But what if you're a student and don't have enough money for a trip？Don...
查看完整题目与答案
【单选题】An appropriate title for the text is most likely to be
A.
The future of the bookstore: A Cultural Destination.
B.
The future of the bookstore: A Cozy Atmosphere.
C.
The future of the bookstore: A Real Cliffhanger.
D.
The future of the bookstore: An Urgent Quest.
查看完整题目与答案
【简答题】I don’t really care how many claws the animal in a comic book (漫画书) has. I’m not overly concerned whether the bird is colored green or grey. In fact I don’t think comic book “collector” really applies...
查看完整题目与答案
【单选题】Facebook can gain various information, except?
A.
What paper book you are reading.
B.
What brands you want to follow.
C.
What is your hobby.
D.
What is your political opinion.
查看完整题目与答案
【单选题】— I’m new in Wuxi. — Take a map of Wuxi with you. You’ll find it of great ________ in helping you to get round Wuxi.
A.
price
B.
cost
C.
interest
D.
importance
查看完整题目与答案
【单选题】在图2-2-11所示的 R L C串联电路中 , 当电源电压为 100V 时 , 测得 U L =120V , u c =40V。已知电阻 R=30 Ω ,则此电路中 x L 和X C 别是
A.
120 Ω ; 40 Ω
B.
40 Ω ; 120 Ω
C.
60 Ω ; 2 0 Ω
D.
20 Ω ;60 Ω
查看完整题目与答案
【简答题】员享有哪些权利？
查看完整题目与答案
【单选题】在 图 示 R , L , C 串 联 正 弦 交 流 电 路 中,各 电 压 表 读 数 如 图 示,当 电 流 频 率 增 大 一 倍 而 保 持 其 有 效 值 不 变 时,各 电 压 表 的 读 数 应 变 为 ( ) 。
A.
V 1 ＝ 200 V                 V 2 ＝ 200 V                 V 3 ＝ 200 V
B.
V 1 ＝ 100 V                 V 2 ＝ 200 V                 V 3 ＝ 50 V
C.
V 1 ＝ 100 V               V 2 ＝ 50 V          V 3 ＝ 200 V
查看完整题目与答案
【简答题】使结构产生内力或变形的原因成为“作用”,作用分为直接作用和( )。
查看完整题目与答案
【单选题】How did the police gain access to Melvin Colons Facebook profile?
A.
He himself carelessly made his online information public.
B.
One of his Facebook friends cooperated with the police.
C.
The judge granted warrant of using his private information.
D.
Facebook made a deal with the police about its users' privacy level.
查看完整题目与答案
相关题目：
【简答题】Traveling can be a way to gain life experiences，especially during Spring Break—a week long school vacation in the United States. But what if you're a student and don't have enough money for a trip？Don...
查看完整题目与答案
【单选题】An appropriate title for the text is most likely to be
A.
The future of the bookstore: A Cultural Destination.
B.
The future of the bookstore: A Cozy Atmosphere.
C.
The future of the bookstore: A Real Cliffhanger.
D.
The future of the bookstore: An Urgent Quest.
查看完整题目与答案
【简答题】I don’t really care how many claws the animal in a comic book (漫画书) has. I’m not overly concerned whether the bird is colored green or grey. In fact I don’t think comic book “collector” really applies...
查看完整题目与答案
【单选题】Facebook can gain various information, except?
A.
What paper book you are reading.
B.
What brands you want to follow.
C.
What is your hobby.
D.
What is your political opinion.
查看完整题目与答案
【单选题】— I’m new in Wuxi. — Take a map of Wuxi with you. You’ll find it of great ________ in helping you to get round Wuxi.
A.
price
B.
cost
C.
interest
D.
importance
查看完整题目与答案
【单选题】在图2-2-11所示的 R L C串联电路中 , 当电源电压为 100V 时 , 测得 U L =120V , u c =40V。已知电阻 R=30 Ω ,则此电路中 x L 和X C 别是
A.
120 Ω ; 40 Ω
B.
40 Ω ; 120 Ω
C.
60 Ω ; 2 0 Ω
D.
20 Ω ;60 Ω
查看完整题目与答案
【简答题】员享有哪些权利？
查看完整题目与答案
【单选题】在 图 示 R , L , C 串 联 正 弦 交 流 电 路 中,各 电 压 表 读 数 如 图 示,当 电 流 频 率 增 大 一 倍 而 保 持 其 有 效 值 不 变 时,各 电 压 表 的 读 数 应 变 为 ( ) 。
A.
V 1 ＝ 200 V                 V 2 ＝ 200 V                 V 3 ＝ 200 V
B.
V 1 ＝ 100 V                 V 2 ＝ 200 V                 V 3 ＝ 50 V
C.
V 1 ＝ 100 V               V 2 ＝ 50 V          V 3 ＝ 200 V
查看完整题目与答案
【简答题】使结构产生内力或变形的原因成为“作用”,作用分为直接作用和( )。
查看完整题目与答案
【单选题】How did the police gain access to Melvin Colons Facebook profile?
A.
He himself carelessly made his online information public.
B.
One of his Facebook friends cooperated with the police.
C.
The judge granted warrant of using his private information.
D.
Facebook made a deal with the police about its users' privacy level.
查看完整题目与答案