Giventhefollowingtwotables: TAB1R1 AAABBCCDETAB2R2 AABBCCD Whichofthefollowingqueriesreturnsthefollowingresultset?RETVALE（）
A. SELECTr1ASretvalFROMtab1INTERSECTSELECTr2ASretvalFROMtab2
B. SELECTr1ASretvalFROMtab1EXCEPTSELECTr2ASretvalFROMtab2
C. SELECTDISTINCTr1ASretvalFROMtab1,tab2WHEREr1<>r2
D. SELECTr1ASretvalFROMtab1UNIONSELECTr2ASretvalFROMtab2
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WhendefiningareferentialconstraintbetweentheparenttableT2andthedependenttableT1,whichofthefollowingistrue?（）
A. ThelistofcolumnnamesintheFOREIGNKEYclausecanbeasubsetofthelistofcolumnnamesintheprimarykeyofT2oraUNIQUEconstraintthatexistsonT2.
B. ThelistofcolumnnamesintheFOREIGNKEYclausecanbeasubsetofthelistofcolumnnamesintheprimarykeyofT1oraUNIQUEconstraintthatexistsonT1.
C. ThelistofcolumnnamesintheFOREIGNKEYclausemustbeidenticaltothelistofcolumnnamesintheprimarykeyofT2oraUNIQUEconstraintthatexistsonT2.
D. ThelistofcolumnnamesintheFOREIGNKEYclausemustbeidenticaltothelistofcolumnnamesintheprimarykeyofT1oraUNIQUEconstraintthatexistsonT1.
生意人指的是（）
A. 企业家
B. 售货员
C. 商贩
YouissuedthefollowingcommandstoconfiguresettinginRMAN; Thenyouissuedthefollowingcommandtotakethebackup: RMAN>BACKUPDATABASEPLUSARCHIVELOG; Whichstatementistrueabouttheexecutionoftheabovecommand?（）
A. ThebackupwillterminatebecausetheFORMATclausewasnotconfiguredforthechannel
B. Itbacksuptwocopiesofdatafilestotapeanddisk,andtwocopiesofarchivedlogfileontape
C. Itbacksupthedatafilesandarchivedlogfilestodisk,makingtwocopiesofeachdatafileandarchivedlogfile
D. Itbacksupthedatafilesandarchivedlogfilestotape,makingtwocopiesofeachdatafileandarchivedlogfile
在牛奶做成酸奶制品的过程中，下列说法不正确的是（）。
A. 营养素增加B
B. 族维生素含量增加
C. 营养价值提高
D. 延长保质期
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