BAI TP THC HANH KHAI THAC VA S DUNG INTERNET Tim kim va tai v may tinh: - Cac video v phan ng th hin tinh cht hoa hoc cua O2, Cl2, Br2, I2, S - Hinh anh: cac dung cu thi nghim hoa hoc, vn nhim mi trng, cac quy trinh san xut axit, xi mng, bang tun hoan cac nguyn t hoa hoc. - Mt s phn mm h tr mn Hoa hoc: Violet, Chemsketch, Crocodile Chemistry.

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CHUYN HAI:

NG DNG CNG NGH THNG TIN V TRUYN THNG TRONG DY HC MN HOA HC 1. Khi nim v Internet Internet l mt mng kt ni ca hng triu my tnh trn ton cu, l mng ca mng. S kt ni ny c th bng cc trng thi vt l khc nhau nh qua ng dy in thoi, ng cp quang hay qua dng sng. Cc my tnh trong mng ny truyn thng vi nhau theo mt ngn ng chung gi l TCP/IP (Transmission Control Protocol/Internet Protocol), khng c my tnh no, khng c ngi no lm ch v iu khin tt c v hu nh c rt t quy nh v vic s dng n. Chnh v n l s kt ni ca hng triu my tnh trn ton th gii nn n l mt mng thng tin khng l. C nhiu dch v khc nhau trn Internet, nhng cc dch v ph bin nht l: WWW (Word Wide Web): Cung cp thng tin dng siu vn bn (Hypertext), kt hp vn bn vi hnh nh, m thanh v c lin kt vi nhau gip truy xut thng tin nhanh. E-mail (Electronic Mail): Gi nhn th trng thi in t trn Internet. Usenet NewsGroup (Cc nhm thng tin): Khi gi thng tin ti dch v ny th mi ngi trn Internet c th c c n v tr li cho ngi gi. Chatting & Conferencing: Cho php ngi s dng tham gia tho lun vi nhau trn Internet. FTP (File Transfer Protocol): c dng ti cc file ln my ch hay ti cc file t my ch xung. Gopher: Truy cp cc tp tin trn Internet bng h thng thc n n gin. Vi cng ngh ngy cng pht trin th nhiu dch v mi cng xut hin trn Internet nh in thoi, hi ngh, truyn hnh... Vi nhiu loi hnh dch v nh vy nhng c th thy Internet c tnh nng rt c bn l xut bn v trao i thng tin hiu qu (nhanh, cp nht v lng ngi tham gia c th n hng triu lt ngi). 39

Vi u th trn m hin nay Internet khng th thiu c trong cc hot ng nghin cu khoa hc v trong dy hc. 2. Lut bn quyn v quyn c s dng trong gio dc Vic khai thc thng tin vi s h tr ca Internet l ht sc thun tin. Tuy nhin, vic khai thc v s dng thng tin ni chung, phc v qu trnh dy hc v nghin cu ni ring rt cn s hiu bit v lut bn quyn. Bn quyn l s c quyn v sn xut hay sao chp, biu din ni cng cng, hoc xut bn cc n phm gc hoc cc tc phm ngh thut. Hu ht mi sn phm c to ra mang tnh cht c nhn sau ngy 01/03/1989 u c bo v bn quyn cho d c c thng bo hay khng. Cng cn lu l gn nh tt c cc thng tin trn Internet l c bo v bn quyn, k c c nhng th c gi ti hp th c nhn qua a ch e-mail. Cho nn hy lun ngh trong u l thng tin ny c bo v bn quyn, tr khi chng ta bit r v n. Tuy nhin trong dy hc, cc gio vin c quyn s dng iu lut s dng hp l. Mc 107, iu khon s dng hp l ca lut bn quyn c khng nh: S c quyn vn c nhng gii hn nht nh l quyn s dng hp l. Vic sao chp, ghi m hoc bi bt c cch no i vi sn phm c bo v bn quyn m nhm mc ch ph bnh, bnh lun, bo co, ging dy (bao gm vic sao chp nhiu bn cho lp hc), xin hc bng hoc nghin cu, c coi l khng vi phm lut bn quyn. C 4 yu t gip xc nh l chng ta s dng ng quyn s dng hp l hay cha (i vi i tng c bo v bn quyn): - Mc ch, tnh cht ca vic s dng i tng, l thng mi hay cho cc mc ch phi li nhun. - Tnh cht ca sn phm c bo v bn quyn (mt s sn phm c bo v bn quyn cao hn so vi ci khc) - n s lng v cht lng phn c s dng (Ch s dng nhng g tht s cn thit) - Vic s dng c nh hng g i vi sn phm trn th trng? Tc gi c b mt khon li nhun tim nng? Do , c coi l s dng hp l nu: - Vic sao chp phc v mc ch gio dc;

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- T liu gc l cc s kin, kh xc nh ngun gc v c xut bn; - Ch s dng mt phn, khng phi tt c; - Khng lm mt th trng tim nng ca sn phm (v d khng cung cp cc bn sao ca sn phm). Hng dn c th cho quyn c s dng hp l i vi gio vin khi s dng cc ti nguyn a phng tin (l hng dn ch khng phi lut): - Gio vin s dng cc sn phm c bn quyn vo xy dng cc bi trnh bi a phng tin nhm h tr qu trnh dy hc ca mnh v bi trnh by c s dng trong cc trng hp sau: ging trc tip trn lp (mt i mt); a cho ngi hc nh mt ngun ti liu h tr hc tp; ging dy t xa (c mt s hn ch). - Gio vin c th s dng cc sn phm ny v thi hn nu vi cc mc ch sau: trnh by vi cc ng nghip; lu li trong h s c nhn phc v mc ch phng vn xin vic, thng tin sau ny. - Gio vin c th s dng cc sn phm ny trong vng 2 nm k t ln u tin s dng chng hng dn trn lp, sau thi gian ny th cn phi xin php cho tng sn phm mt. - Gii hn ln ca cc ngun ti nguyn c s dng: Phim/nh ng: ti a 10% hoc 3 pht ca phim/nh ng c bn quyn, tu iu kin no nh hn. Ti liu vn bn: ti a 10% hoc 1000 t ca mt on t liu, tu iu kin no nh hn. Ti liu dng th ca: Ton b bi th vi iu kin bi th t hn 250 t, nhng khng c s dng qu 3 bi th ca cng mt tc gi hoc khng c qu 5 bi th ca cc tc gi khc nhau trong cng mt tuyn tp. Vi cc bi th di: ti a di trch dn l 250 t, nhng khng qu 3 trch dn ca cng mt tc gi hoc khng qu 5 trch dn ca cc tc gi khc nhau trong cng mt tuyn tp.

- m nhc, li bi ht, phim m nhc: ti a 10% nhng khng qu 30 giy nhc v li t mt tc phm m nhc. Bt k s thay i i vi mt tc phm m nhc s khng lm thay i giai iu nn tng hoc tnh cht c bn ca tc phm.

41

-

Tranh v nh: Mt bc tranh hay nh c th c s dng ton b nhng khng c hn 5 bc tranh hay nh ca cng mt tc gi, khng hn 10% hay 15 tranh/nh t mt b su tp tu iu kin no nh hn. S liu: ti a 10% hoc 2500 trng hoc d liu t mt c s d liu hoc bng d liu, tu iu kin no nh hn.

-

Tuy nhin, vi phn mm my tnh th khng th p dng iu lut v s dng hp l c. Cc n v gio dc t nhn hay nh nc u khng c ngoi tr i vi lut bn quyn v phn mm. Khi mua mt phn mm tc l ta ch mua giy php (license) s dng phn mm ch khng phi ta s hu phn mm . Mi ngi khi mua giy php s dng mt phn mm u c quyn ci phn mm trn mt my tnh v to mt bn sao phn mm vi mc ch lu tr d phng, cn ngoi mc ch trn th cn phi c s chp thun ca ch s hu bn quyn. Vi phn mm s dng th (Shareware, Trialware) th n ch min ph vi mc ch nh gi v thng ch c th trong thi gian ti a khng qu 30 ngy, nu mun tip tc s dng ta phi tr tin mua giy php s dng phn mm . Vi phn mm min ph (Freeware) cng vn phi tun theo lut bn quyn l c th pht tn phn mm thoi mi, c tip tc pht trin phn mm nhng khng c bn. Ch c phn mm m (Public Domain Software) mi thc s min ph, bn quyn s dng b loi b; khng b hn ch v pht tn, ph bin; c th sa i phn mm gc, pht trin phn mm mi da trn n v c bn sn phm ny. Trong tt c cc trng hp trn, vic s dng cc sn phm c bn quyn u phi c s ghi nhn v quyn hn v s cng nhn, c th: - Thng tin v s hu bn quyn: bt u bng k hiu (K hiu bn quyn), nm pht hnh v tn ch s hu bn quyn. Ghi nhn ngun t liu gm: tn tc gi, tiu , nh xut bn, thi gian xut bn. Vi t liu dng nh th tn tc gi phi i km cng vi nh. Vi ti liu t Internet th cch trch dn c th gm: tn website, a ch website, m t ngn v ni dung website. Hoc tn tc gi, tn t liu, tn website, ngy ng, ngy sa i, tn t chc s hu website, ngy truy cp. 3. S dng Internet khai thc thng tin 42

-

c th tip cn vi Internet th u tin chng ta cn mt chng trnh my tnh gi l trnh duyt web (Web Browser). Hin nay c mt s trnh duyt web ph bin nh Netscape, Mozilla Firefox hay Internet Explorer. Nhng c l ph bin nht hin nay Vit Nam l trnh duyt Internet Explorer v n c tch hp sn trong h iu hnh Microsoft Windows. Sau y ta s lm quen vi cch s dng Interner Explorer: Khi ng Internet Explorer: Vo Start chn Programs (All Programs) Chn Internet Explorer, lc s bt ra ca s Internet Explorer (hnh 1, tu thuc vo trang ch mc nh m c th hnh minh ho s khc)

Hnh 1

Trong ca s Internet Explorer th trn cng l thc n (Menu), ngay di thanh thc n thng l thanh cc nt iu khin chun (Standard Buttons), di thanh ny thng l thanh a ch (Address Bar) (Hnh 2) v di y ca s thng l thanh trng thi (Status Bar) cho thy qu trnh ti xung ca tng trang web. truy cp mt website bng Internet Explorer ta c th s dng mt trong cc phng php sau: - G a ch trang web vo thanh a ch (Address Bar). - Nhp chut vo mt siu lin kt. - Chn mt trang t danh sch History. 43

- Chn mt v tr (site) t th mc Favorites. - Dng thanh cng c lin kt (thanh cng c Links) - Dng cng c h tr tm kim (Search Assistant).

Thanh thc n Thanh cc nt iu khin Thanh a ch Hnh 2

Phn sau y ta s lm quen phng php dng thanh a ch: Bt v tt thanh a ch th lm nh sau: Trn thanh thc n nhp chut vo View Toolbars chn Address Bar (hnh 3). Nu bn cnh dng ch Address Bar nu khng c du kim () th thanh a ch s b tt i, cn nu c du kim th thanh a ch s c bt ra.

Hnh 3

n mt website no trn Internet bn g a ch ca n vo Address, sau nhn nt Go hoc g phm Enter. Cc a ch trn Internet cn c gi l URL (Uniform Resource Locators). a ch y ca mt website trn Internet c th c dng nh sau: http://www.moet.gov.vn (a ch ca website B Gio dc v o to). Ta c th phn tch a ch ny nh sau: http l HypetText Transport 44

Protocol l giao thc ca trang web; www l dng dch v world wide web; phn cn li ca a ch c gi l tn min (domain name), tn min ni ln n l dng web g, v d trong trng hp ny n l .gov tc l thuc nh nc (government). Trong Internet Explorer bn khng cn g http trong a ch, tr a ch ca site dng giao thc khc, nh FTP. Phn ln bn ch cn g a ch bng ch thng, ngoi tr mt s a ch c phn bit ch hoa ch thng. Mt lu na l mc d c rt nhiu website trn Internet nhng chng phn bit rt cht ch nh dng a ch, v vy bt buc phi g chnh xc dng a ch n tng ch ci nu khng chng ta s khng n c v tr nh mong mun hoc khng th tm thy v tr . Nh trn ni Internet l mt bin thng tin, nhng cng chnh v l m vic tm ra mt thng tin cn thit khng phi d dng v i khi n ging nh vic m kim y b, nu khng bit cch tm kim. tm n ngun thng tin cn thit trn Internet th s c hai cch c bn sau: - Cch 1: tm kim tnh tc l s dng nhng cun trang vng Internet hoc s a ch Internet. y cc ngun thng tin c nhm li theo nhiu tiu ch khc nhau v km theo l a ch cc website lin quan n nhm thng tin . Vic d tm thng tin ging nh s dng Nin gim in thoi, tc l ta nh v thng tin trong sch trc sau mi s dng n my tnh, trnh duyt n ngun thng tin. Theo cch ny c u im l c th nhanh chng n vi ngun thng tin cn tm nu nh n c cung cp y trong sch. Nhng cng c nhc im l c th dng a ch website trong sch li thi, v mt l do no m website thay i a ch hoc khng tn ti na (y cng l mt c tnh ca ngun thng tin trn Internet), thng tin v ngun thng tin trn Internet thay i hng ngy, hng gi. gim bt nhng ri do trn th ngi ta s dng cch tm kim th hai, tm kim ng. - Cch 2: tm kim ng tc l tm kim trc tuyn. Chng ta s dng nhng a ch website c th gip chng ta t chc qu trnh tm kim ca mnh. Ti cc dng a ch ny chng ta s n cc website m cho php tng tc vi chng ta bng cc t kho, ngi ta gi chng l cc cng 45

c tm kim (Search Engine). Phn sau y chng ta s tp trung vo cch tm kim ng, s dng mt s cng c tm kim ph bin. 3.1. S dng cng c tm kim Nhng dng a ch sau y cho php chng ta n vi mt s cng c tm kim: www.google.com.vn (Google); www.yahoo.com (Yahoo); www.altavista.com (Alta Vista); www.hotbot.com (Hot Bot); www.snap.com (Snap) Theo gio trnh Dy hc ca Intel c th phn loi cc cng c tm kim nh bng 1.Bng 1: Phn loi mt s cng c tm kim Nu bn Loi cng c tm kim mun Duyt tm theo Yahoo Lycos ch www.yahoo.com/ www.lycos.com/ rng Tm mt AltaVista Excite ch www.altavista.com/ www.excite.com/ hp Tm kim Metacrawler tng Ask Jeeves http://www.metacrawler.co hp/siu www.askjeeves.com m/ tm kim Duyt cc ch Schrocks Guide Blue Webn v ti http://school.discovery.com/ http://www.kn.pacbell.c nguyn schrockguide/ om/wired/bluewebn/ v gio dc Tm cc ti liu v K-12 Weblinks Database EvaluTech bi bo www.itrc.ucf.edu/k12db/ www.evalutech.sreb.org/ v gio dc

Google www.google.com.vn Go (Infoseek) http://www.go.com/ All the Web (Fast Search) http://www.alltheweb .com/ Connections http://www.mcrel.org /resources/ links/hotlinks.asp

Free www.ed.gov/free/

Mi mt cng c tm kim c cch t chc tm kim khc nhau, giao din ngi dng khc nhau v i khi kt qu cc loi thng tin tm kim c cng khc nhau. chnh l l do ti sao li c bng phn loi cng c 46

tm kim nh trn. V thc cht bng trn cung cp cch tm kim tnh trc khi n vi cch tm kim ng. giao tip vi cng c tm kim chng ta phi nhp cc t kho (t ch cht lin quan n ch cn tm kim) vo tm kim. T kha c th l ting Vit v cc ngoi ng khc, ch yu l ting Anh. Tuy nhin, v c s d liu bng ting Vit trn mng cn cha nhiu, cho nn tt nht chng ta s dng cc t kho bng ting Anh trn mi loi cng c tm kim. Sau y chng ta s lm quen cch s dng hai cng c tm kim ph bin l: Google (a ch: www.google.com.vn) v Yahoo (a ch: http://vn.search.yahoo.com/) 3.1.1. Tm kim c bn S dng Google: bt Interner Explorer, g dng a ch ca Google vo thanh a ch, giao din cng c tm kim s hin ra nh hnh 4. - Trong ca s cng c tm kim ta s thy mt c biu tng con tr chut nhp nhy , l tm kim (Searching Box). tm kim c 4 tu chn l: Internet (tm kim cc trang web v tm thng tin ni chung); Hnh nh (tm kim thng tin dng hnh nh); Nhm (tham gia, to nhm trao i thng tin theo ch ); Th mc (tm thng tin i theo dng cy th mc, sp xp, phn loi thng tin theo cc nhm ch ). khai thc thng tin phc v cc bi dy Sinh hc th chng ta thng s dng thuc tnh tm hnh nh, v s dng cc thuc tnh khc i hi phi c trnh ting Anh nht nh mi c th khai thc thng tin hiu qu.

tm kim, mun n ty chn no th nhp chut vo ty chn

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Hnh 4

- Chng ta th tm kim hnh nh v ADN: + T kho ting Anh l DNA. + Chn tu chn tm kim trn Google l Hnh nh + G t kho vo tm kim v nhn vo nt Tm hnh nh hoc nhn phm Enter + Quan st kt qu. - Chng ta tm thng tin v ADN: + T kho ting Anh l DNA. + Chn tu chn tm kim trn Google l Internet. + G t kho vo tm kim v nhn vo nt Tm kim vi Google hoc nhn phm Enter. So snh kt qu ca hai cch tm kim c th d dng nhn thy tm hnh nh d dng hn rt nhiu v n trc quan. S dng Yahoo: bt Interner Explorer, g dng a ch ca Yahoo vo thanh a ch, giao din cng c tm kim s hin ra nh hnh 5.

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Hnh 5

- tm kim ca Yahoo Search Vit Nam tng t nh Google Vit Nam. im khc y l Yahoo tch hp thm ty chn tm kim Video. Nu s dng Yahoo quc t (www.yahoo.com) th s tnh nng tm kim s nhiu hn nh: tm kim theo cc vng a l (Local) hay tu chn tm kim gip mua sm online (Shopping); tm kim m thanh (Audio); tm kim theo th mc (directory)... - Vic tm kim bng Yahoo ging ht nh bng Google. - Chng ta lp li cc bc tm kim nh trn v so snh kt qu ca Yahoo vi Google s thy chng tng t nhau. Vy c th tng kt cc bc tm kim c bn nh sau: Bc 1: Da trn ni dung xc nh t kho/cm t kho. Bc 2: S dng cc cng c tm kim ng vi t kho . 3.1.2. Tm kim nng cao Vic tm kim c bn nh trn xem ra c v n gin. Nhng thc cht kt qu ca vic tm kim ph thuc rt nhiu vo t kho, c th l tnh cht ca t kho. Nu t kho lin quan n chuyn mn hp th kt qu tm kim s d dng t c, nhng nu t kho lin quan n nhiu chuyn ngnh (t kha a ngha) hay l mt khi nim rng th vic tm ra thng tin cn thit li khng h n gin. V d: t kho chuyn ngnh hp nh ADN, ARN hay SUCCESSION (din th sinh thi) th kt qu s rt r; nhng nhng t kho nh gio dc (Education), cng ngh (Technology) th kt qu tm kim s rt nhiu v ng ngha vi nhiu thng tin nhiu. c th nhanh chng tm ra thng tin cn thit th trong nhiu trng hp chng ta phi s dng cc bin php tm kim hiu qu hn, mt trong nhng bin php l chng ta s dng logic Boole hoc gi Boole (Pseudo-Boole Logic). Cch s dng logic Boole c trnh by trong bng 2:Bng 2: Logic Boole v gi Boole

Logic Boole (lun vit hoa) AND (Google t

Kt qu

Gi logic Boole

Ch th hin phn giao ca hai tp hp . Hay cch khc l kt qu 49

S dng k t +. V d: Gio dc +Cng ngh

ng thm lit k cc trang vi s hin din AND gia ca c hai yu t trong cu lnh cc t) tm kim. V d: Gio dc AND Cng ngh (thng tin lin quan n c cng ngh v gio dc) NOT Kt qu s loi b nhng yu t ng ngay sau ch NOT. V d: Virus NOT Computer (Thng tin lin quan n virut nhng khng tnh virut my tnh) OR

(Cu lnh ny dng cho: Yahoo, Lycos, Excite, Alta Vista, Infoseek - xem bng 1)

S dng k t -. V d: Virus Computer (Cu lnh ny dng cho c Google, Yahoo, Lycos, Excite, Alta Vista, Infoseek - xem bng 1) Kt qu m rng. Nhng trang th S dng k t , hin mt trong cc yu t s V d: cats, kittens c gi ra. Cu lnh ny ch dng cho V d: cats OR kittens (Nhng Infoseek thng tin lin quan n mo hoc mo con). Cu lnh ny ch dng cho Excite. i vi Google th phi tm kim ring r. Vi Alta Vista phi dng du cch thay cho OR. Vi Yahoo v Lycos phi dng ch tm kim nng cao (c bn sau y)

Ngoi logic Boole nh trnh by trn th cn nhiu dng cu lnh cho php chnh xc ho qu trnh tm kim: - Du ngoc kp: tm chnh xc t, cm t nm trong ngoc kp. V d: Chu trnh t bo. - Dng php NEAR: cho php tm nhng ni dung m t kho nm gn nhau. N c ngha trong trng hp ta khng nh ht cu vn no trong mt ni dung nht nh. V d: T bo gc NEAR t bo da (Ni v t bo gc lin quan n t bo da). - Nhng cu lnh ca logic Boole hay cc dng cu lnh khc khng phi tt c cc cng c tm kim u h tr. Trong trng hp ta cn 50

bit k thut tm kim nng cao ca cc cng c (Advanced Searching). Sau y l cch dng tnh nng tm kim nng cao ca Google v Yahoo. Tnh nng tm kim nng cao ca Google: + Vo trang ch Google (www.google.com.vn) + Nhp chut vo nt Tm kim nng cao (hnh 6) + Lm theo hng dn trn mn hnh (hnh 7) + Vic b sung thm nhiu chi tit khi tm kim s cng lm chnh xc ho qu trnh tm kim.

Hnh 6

Tnh nng tm kim nng cao ca Yahoo: + Vo trang ch ca Yahoo (http://vn.search.yahoo.com) + Nhp vo nt Tm kim nng cao (hnh 8) + Lm theo hng dn trn mn hnh (ting Vit)

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Hnh 7

Hnh 8

Qu trnh tm kim thng tin trn Internet c th s ha n gin nh sau:Xc nh t kho, cm t kho da trn ch Tm kim nng cao

Tm kim c bn

Cha tm c

Tm c Lu gi thng tin

3.2. Lu gi thng tin t Internet Vic tm kim thng tin trn Internet l mt bc, nhng quan trng hn c l chng ta khai thc ngun thng tin phc v bi dy, c bit l cc ti nguyn dng hnh nh. C 3 cch c bn lu gi thng tin t Internet v my tnh. 3.2.1. Lu gi ton b trang web Trong nhiu trng hp chng ta nhn thy tt c cc thng tin trn mt 52

trang web no l cn thit (bao gm c hnh nh v ch vit), lc ta tin hnh lu gi ton b trang web. Trong ca s Internet Explorer vo File trn thanh thc n chn Save As chn ng dn mun lu thng tin Trong phn Save as type ta chn kiu nh dng mun lu li. Kiu Text File s lu thng tin di dng ch v s mt mi nh dng hnh nh nhng li c th m li bng bt c phn mm c ch no nh Word, Notepad... Cn li cc kiu khc u dng web v khi m cn phi s dng mt trnh duyt (iu ny cng khng c g ng ngi v hin nay tt c cc my ti thiu u c Internet Explorer) (hnh 9, hnh 10 v hnh 11). 3.2.2. Lu gi mt phn trang web Trong nhiu trng hp ta li ch mun lu gi mt phn trang web (ch yu l phn ch) th cch lm nh sau: - Dng chut bi en ton b vng vn bn m ta mun lu gi - Chn Edit trong thanh thc n chn Copy (hoc kch chut phi ri chn Copy hoc nhn t hp bn phm Ctrl+C) (hnh 12)

Hnh 9

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Hnh 10

Hnh 11

Hnh 10

- Khi ng phn mm MS.Word (hoc Notepad; Wordpad...., chng trnh x l vn bn) - Chn Edit Paste (hoc nhn t hp phm Ctrl+V) - Lu li file vn bn ny.

54

Hnh 12

3.2.3. Lu hnh nh Khi s dng cc cng c tm kim v chng ta tm c nhng hnh nh mong mun th cch lu nh xung my tnh ca chng ta v nguyn tc chung c th thc hin theo cc bc c bn sau: chn vo nh nhp chut phi chn Save Picture As chn ng dn n v tr lu nh nhp nt Save l c. Sau y chng ta s hc cch lu mt nh c th sau khi s dng cng c Google tm kim. - Ch : hnh nh v cu to tim - T kho: heart anatomy - S dng cng c Google v kt qu tm kim hnh nh th hin nh hnh 13. - Nhp chut vo mt hnh ng nht (hnh 14) - Nhp chut vo nt Xem hnh c y (hnh 15) - Nhp chut phi chn Save Picture As (hnh 16) - Chn ng dn n v tr t nh - Nhp nt Save (hnh 17)

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Hnh 13

Hnh 14

Hnh 15

56

Hnh 16

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Hnh 17

Cc bc lu nh nh trn hon ton c th p dng vi cng c tm kim Yahoo cng nh cc cng c khc. Cn vic lu m thanh hay on phim th i hi trang web phi cho php ti (download) m thanh hay on phim xung. V cch lu m thanh hay on phim th cng tng t nh lu tranh nh, tuy nhin thay v chn vo Save Picture As (nh hnh 16) th chn vo Save Target As. Cc bc cn li tin hnh nh lu tranh nh l c. 3.3. nh gi thng tin trn Internet Thng tin trn Internet rt nhiu nhng khng phi mi thng tin lun lun ng v lun lun ng tin. Hy ghi nh rng Internet khng h c bt c quy nh no v khng c ai l ngi thc s iu hnh n. Bt c ai cng c th xut bn thng tin ln trn Internet m khng h b kim duyt, do nhng thng tin c th chnh xc hoc khng chnh xc, c ngha hoc khng c ngha. V vy, vic nh gi cht lng thng tin trn Internet l ht sc quan trng v chng ta phi nh gi thng tin trc khi quyt nh lu gi n hay khng. nh gi thng tin trn Internet, chng ta nn suy ngh theo nhng gi sau y: - Ngun thng tin. Trang web ny c iu hnh bi c nhn hay t chc? T chc l ca nh nc hay t nhn? L phi li nhun hay c li nhun? - Lun bit r mnh ang u trn Internet. Bi trong nhiu trng hp mc d bn xut pht t mt trang web chnh thng nhng do theo cc ng lin kt m bn li c th n mt trang web hon ton khc v thm ch l rt l ci. Hc cch c a ch web d nhn bit mnh di chuyn gia cc trang web nh th no. - Nhn bit nhanh website qua tn min. V d: .com l ca cc t chc thng mi (commercial); .org l cc t chc ni chung (organization); .net l cc t chc mng; .gov l ca chnh ph (government); .edu l ca cc t chc gio dc (education); .ac l ca cc vin nghin cu chuyn su (academy)... 58

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