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【单选题】
若关系中的某一属性组的值能惟一地标识一个,则称该属性组为( )。A.
主码
B.
候选码
C.
主属性
D.
外码
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举一反三
【简答题】案例:江苏东台市新农镇临海青年农民崔益祥从邻乡农民邓瑞云土法上楼板导致楼房倒塌一死三伤的重大事故中得到启示:中国有2.2亿个家庭在农村,如果有厂家专为农村建筑开发一个起吊安装楼板的自动化设备,将有一个了不起的市场空间。 有了这样的想法,崔益祥筹资10万元开发费,在南京建工学院专家教授指导下顺利开发成功全自动楼板吊装机,这种由手扶拖拉机,发电机,卷扬机,自动伸缩塔,空中平面输送轨道,电控箱等组合而成...
【简答题】She will be here in an hour to you. 2. The cookies are thickly with chocolate. 3. Cheap imported goods are the market. 4. He received a of grateful telegrams and letters. 5. She has a very temperature...
【简答题】Translate the following sentences into Chinese.(将下列句子翻译成中文) 1. You have to work hard if you want to succeed in your courses. 2. I managed to pass the final exam with a fairly good grade. 3. Shortly af...
【多选题】塑性是指材料在外力作用下发生塑性变形而不被破坏的能力。也就是说，材料 持续 发生塑性变形的量越大，塑性就越 （好，差）。而发生塑性变形所需的外力大小与塑性的好与差无关。容易发生塑性变形的材料，其塑性未必就好，反之亦然。反映塑性好坏的指标有两个，即断后 和截面收缩率，前者的代号为δ，后者的代号为ψ，它们都是没有单位的量。
A.
好
B.
伸长率
【简答题】Readin g C omprehension Directions: In this part, there are two passages followed by questions or unfinished state ments, each wi th f our suggested answers marked A, B, C, and D . Choose the one th a...
【简答题】江苏东台市新农镇临海村青年农民崔益祥从邻乡农民邓瑞云土法上楼板导致楼房倒塌一死三伤的重大事故中得到启示：中国有2.2亿个家庭在农村，如果有厂家专为农村建筑开发一个起吊安装楼板的自动化设备，将有一个了不起的市场空间。有了这样的想法，崔益祥筹资10万元开发费，在南京建工学院专家教授指导下顺利开发成功全自动楼板吊装机，这种由手扶拖拉机、发电机、卷扬机、自动伸缩塔、空中平面输送轨道、电控箱等组合而成的成套...
【简答题】从B栏中选出A 栏的答语。 A ( ) 1. May I go shopping? ( ) 2. If you work hard in school, you may go with us. ( ) 3. When do you leave for America? ( ) 4. How far is it from China to Canada? ( ...
【简答题】G eometric figures are widely used in various aspects of people ’ s life, such as patterns on sweaters, shapes of desks and even the shape of a birthday cake. In addition, geometric figures can be see...
【多选题】Fill in the blanks with the proper words given below, changing the form if necessary.(请用下列单词的正确形式填空) comfortably; instruction; apologize; residence; available; accommodation; service; additional; inco...
A.
accommodation
B.
entrance
C.
residence
D.
services
E.
instruction
F.
additional
G.
apologize
H.
inconvenience
I.
comfortably
J.
available
【简答题】词形变换。 1. If you work hard, you'll___________(success) in the exams. 2. Thank you very much for giving us some___________(value) advice. 3. One of my__________(hobby) is to collect stamps. 4. You must ...
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