所有可选项缺省时,数据库记录输出命令LIST 和 DISPLAY 的区别是
B
暂无解析
设 U 是所有属性的集合, X、Y、Z 都是 U 的子集,且 Z=U-X-Y 。下列关于多值依赖的叙述中,不正确的是
下列叙述中,()不是目前数据库应用系统开发工具存在的主要问题
I______thatIwereabird.
Lastnighthesawtwodark_____enterthebuilding,andthentherewastheexplosion.
—Doyoumind__________here?
—________.
Weregret______unabletoagreetothebuyer'srequestasstatedintheL/Cstipulationsforinsurancetobecovereduptotheinlandcity.
Onwhichdayisthemeetinggoingtotakeplace?
Whichoneisnotthefunctionsofthenonverbalcommunication;()
Wherewillthemeetingtakeplace?
Bodylanguagealsocalled:
Ioftenthoughtofmychildhood,____Ilivedonafarm.
Whatisagenerallyacknowledgedasthemostpowerfuladvertisingmediumandreachesabroadspectrumofconsumers.()