【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】Not only help him with his maths, but you should help him with his English. [ ]
【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】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