单项选择题 ViewthefollowingSQLstatements：TransactionT1INSERTINTOhr.regionsVALUES（5，’Pole’）；COMMIT；TransactionT2UPDATEhr.regionsSETregion_name=’Poles’WHEREregion_id=5；COMMIT；TransactionT3UPDATEhr.regionsSETregion_name=’NorthandSouthPoles’WHEREregion_id=5；YouwanttobackouttransactionT2.Whichoptionwouldyouuse？（）A.Itispossible，buttransactionT3alsobacksout.B.ItispossiblewiththeNOCASCADE_FORCEoption.C.ItispossiblewiththeNONCONFLICT_ONLYoption.D.ItisnotpossiblebecauseithasconflictswithtransactionT3.

单项选择题 YouarecreatinganewformfortheOrderEntryapplication.Youdefinearecordgroupthatwillbecreatedwhentheformisexecutingthisbuiltin:CREATE_GROUP(rg_emplist,global_scope)Whichform(s)intheapplicationwillhaveaccesstothisrecordgroup?（）A.Allformsintheapplication.B.Anyformsopenedbytheuserwhoinitiatedtherecordgroup.C.OnlytheformissuingtheCREATE_GROUPbuilt-in.D.Anyformsreferencedbytheformthatcontainstheprocedure.

单项选择题 Whenimportingatableintoadatabase，theimportprocessperformsthesetasks：1.Triggersareimported.2.Dataisimported.3.Newtablesarecreated.4.Indexesarebuilt.5.Anybitmap，functional，and/ordomainindexesarebuilt.6.Integrityconstraintsareenabledonthenewtables.Whichoptionshowsthetasksintheorderinwhichtheyareperformed？（）A.2，3，4，1，6，5B.3，2，4，1，6，5C.3，2，6，4，1，5D.4，2，3，1，5，6

单项选择题 mpeg、mpg或dat格式是运动图像专家组(MPEG)格式，釆用这种格式的家用设备不包括____。

单项选择题 目前许多外部设备(如数码相机、打印机、扫描仪等)采用了USB接口，下面关于USB的叙述中，错误的是( )。