【TheInternetisanoceanofknowledge．Itcanbehelpfultopeopleallovertheworld．Thisis，infact，whyithasbeen（21）___forsolong．ButtherearesomepartsoftheInternetthatmakeitdisadvantageousforcertain（22）___groups】

　　TheInternetisanoceanofknowledge．Itcanbehelpfultopeopleallovertheworld．Thisis，infact，whyithasbeen （21）___forsolong．ButtherearesomepartsoftheInternetthatmakeitdisadvantageousforcertain（22）___groups．

　　Asahugedatabase （资料库） of（23）___，theInternetcanbeusedtodrawfactsaboutanything．Anditkeepsyouup-to-datewithalltheeventsthatare （24）___throughouttheworldintheformofnews，（25）___andvideos．Newspapersarecertainlya（n）（26）___partofthisprocess，buttheInternetgetsupdatedwiththe（27）___newsmuchfasterthannewspapersget （28）___．Sothenewsthatyougetismuch （29）___．TheInternetisalsoagreatwayto（30）___withyourfriendsandfamilymemberswholivefaraway．（31）___familyandfriends，theInternetalsoformsaperfectmedium （媒介） forbusinessmeetingsthatareheldacrosscountries，whichhasbecomevery （32）___thesedays．

　　However，therearealsoafew （33）___inusingtheInternet．Thefirstoneistheexposure（暴露） tosomeunhealthycontents．Thisisamajorproblemthat （34）___parentsofallteenagers．TheInternetisalsoareadilyavailablesourceofvideogames，（35）___violentgames．Childrenwhoareattheageofexperimentingmay （36）___gettingaddictedtosomeofthegames．AndtheInternetisasourceofcomputerviruses（病毒） whichcanbea （36）___ toyourcomputer，and （38）___yoursystemintheend．（39）___，itisimportanttohaveanantivirusprogramonyourcomputer．Thesearesomeofthethingsworryingpeopleaboutthe （40）___oftheInternet．Soyoumaythinktwicebeforemakingyourownchoice．

　　21．A．amusingB．confusingC．popularD．difficult22．A．ageB．sexC．familyD．income23．A．opinionsB．LanguageC．instructionsD．information24．A．runningoutB．takingplaceC．breakingoutD．comingtrue25．A．booksB．lettersC．picturesD．diaries26．A．importantB．differentC．missingD．unusual27．A．localB．greatC．biggest