【单选题】在数据库设计中用关系模型来表示实体和实体间的联系,关系模型的结构是
【单选题】According to the information from the airline, a small sinking part of the runway of the airport is _____________ for the accident.
【单选题】在数据库设计中用关系模型来表示实体之间的联系。关系模型的结构是____。
【单选题】Everyone of us lives and works on a small part of the earth's suce, moves in a small circle, and of these acquaintances knows only a few intimately. Of any public that has wide effects we see...
A.
man's life is also insignificant.
B.
man's opinions can not be accurate at all.
C.
human observations in general are all but partial.
D.
man can not have any opinion.
【判断题】由于人们对空气干湿程度的感受与空气中水汽的绝对数量直接相关,所以采用绝对湿度来判断空气的干湿程度。( )
【单选题】在数据库设计中用关系模型来表示实体和实体间联系,关系模型的结构是