若含有n个顶点的无向图恰好形成一个环,则它有__________棵生成树。
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连通图的生成树包含了图中的所有顶点。
A. 对
B. 错
Task 1 Word SelectionFill in the blanks with words given below. Change the form where necessary.1. Sheisreluctanttodiscussthe_____________oftheplay.2. _____________numerousfailures,theycontinuedtoconducttheexperiment.3. Themain_____________ofthemerchantbanksistoraisecapitalforindustry.4. Ihopeinyearstocomehewill_____________onhisdecision5. The temperature of this city _____________ from 0℃ to 30℃..6. You will be informed of the details at the _____________ time.7. Thenovelpresentsone_____________ofthereforminthecountryside.8. Whenweinvestinlearningand_____________,weinvestinhumandignity,developmentandpeace.9. We will resolutely ____________ our internationalist duty no matter whathappens.10. Thechildisvery_____________andevenhisfathercannotmanagehim.
Task 3 Word FormationComplete each of the following sentences with the proper form of the word given in brackets.1. The_____________forthecourseinvolveswrittenassignmentsandpracticaltests.(assess)2. Contrarytogeneral_____________,heannouncedthatallfourhadgiventheirapproval. (expect)3. Responsibility,dialogue,actionandreportingarethekeyelementsina_________circlethroughwhicheveryonebenefits. (virtue)4. Ideasaboutthesocialsignificanceof____________havechangedovertime.(religious)5. Thenew-mediaindustryattractsyoungand_____________people. (create)6. Theybumpedhimoffbecauseheknewtoomuchabouttheir_____________activities. (legal)7. TheFestivalOfAsianArts&Musicwillincludetwodaysoflive_____________.(perform)8. Oneofthedrivingforcesbehindthisrecent___________isthegrowthofservices.(expand)9. Akeyissueforhighereducationinthe1990'sistheneedforgreater__________ofcourses (diverse)10. His_____________wasbecomingincreasinglyirrational.(behave)
执行DROP USER语句删除用户,需要拥有的权限是
A. DROP USER权限
B. DROP TABLE权限
CREATE USER权限
DELETE权限