【判断题】Excel2016程序生成的文档默认扩展名是.xls。
【单选题】She’s an excellent swimmer and he’s a fantastic runner. They’re both so...
【判断题】Excel 2013程序生成的文档默认扩展名是.xls。
【单选题】He has his faults, but _____ he is an excellent teacher and we all respect him.
【简答题】设关系R和S的属性个数分别为r个和s个,其中两个关系只有一个相同的属性,那么 操作结果的属性个数为______。
【判断题】Excel 2013程序生成的文档默认扩展名是.xls。A. 对 B. 错
【简答题】A.Because there is an excellent bus service. B.Because there is an excellent railway service. C.Because there is all excellent subway system. D.Because taxi system there isn't convenient.
【单选题】My neighbor ______ her own daughter as an excellent secretary!
【单选题】设关系R和S的属性个数分别为r个和s个,那么(R×S)操作结果的属性个数为( )。
【简答题】设关系R和S的属性个数分别为r个和s个,其中两个关系只有一个相同的属性,那么R S操作结果的属性个数为【 】。