imAginE FishErmEn wAlking Down to thE sEAshorE, rEADy to CArry out thEir EArly morning routinE oF prEpAring thEir BoAts AnD nEt. {{u}} (71) {{/u}} thEy hopE For A gooD CAtCh oF Fish.But to thEir {{u}} (72) {{/u}}, A horriBlE sight mEEts thEir still slEEpy EyEs. thousAnDs oF Fish hAvE wAshED {{u}} (73) {{/u}}DEAD、thE CAusE oF this mAss DEstruCtionA、rED tiDE! rED tiDEs ArE A gloBAl {{u}} (74) {{/u}}. thEy hAvE BEEn oBsErvED on Both thEAtlAntiC AnD thE pACiFiC CoAsts oF thE unitED stAtEs AnDCAnADA、thEy hAvE Also {{u}} (75) {{/u}} in mAny othEr plACEs. though rElAtivEly FEw pEoplE ArE {{u}} (76) {{/u}} thEm, rED tiDEs ArE not nEw. in thE philippinEs, A rED tiDE wAs First sEEn in thE provinCE oFBAtAAn in 1908. sinCE thEn, rED tiDEs hAvE BEEn sEEn in mAny othEr {{u}} (77) {{/u}}.A、philippinEs rED tiDE ExpErt tolD us thAt" {{u}} (78) {{/u}} thE Fish kills, thE philippinEs hAs DoCumEntED 1,926 CAsEs oF DEAD shEllFish poisoning CAusED By rED tiDEs". thE tErm "rED tiDE" {{u}} (79) {{/u}} thE DisColorAtion oF wAtEr thAt somEtimEs oCCurs in CErtAin ArEAs oF thE oCEAn or sEA、Although thE Color is oFtEn rED, it mAy Also BE {{u}} (80) {{/u}} oF Brown or yEllow. thE worlDBookEnCyClopEDiA rEports thAt "thE DisColorED ArEAs mAy rAngE From {{u}} (81) {{/u}} A FEw squArE yArDs to morE thAn 2,600 squArE kilomEtErs". whAt CAusEs suCh DisColorAtion rED tiDEs ArE gEnErAlly CAusED By sEvErAl {{u}} (82) {{/u}} oF singlE-CEllED orgAnisms. thEsE tiny orgAnisms hAvE hAir-likE projECtions whiCh thEy usE to {{u}} (83) {{/u}} thEmsElvEs in wAtEr. thErE ArE ABout 2,000 vAriEtiEs oF thEsE orgAnisms, 30 oF whiCh CArry poisonous {{u}} (84) {{/u}}. thEsE minutE orgAnisms usuAlly stAy in wArm wAtErs with high ContEnt oF sAlt. A、rED tiDE oCCurs whEn thErE is A suDDEn AnD rApiD {{u}} (85) {{/u}} oF thEsE orgAnisms. thE ConCEntrAtion oF thEsE orgAnisms mAy {{u}} (86) {{/u}} to 50,000,000 pEr quArt oF wAtEr!Although sCiEntists Do not Fully unDErstAnD why this hAppEns. it is known thAt thEsE orgAnisms {{u}} (87) {{/u}} whEn CErtAin ConDitions simultAnEously AFFECt thE wAtEr. thEsE inCluDE ABnormAl wEAthEr, {{u}} (88) {{/u}} tEmpErAturEs, An ovErsupply oF nutriEnts in thE wAtEr, A gEnErous {{u}} (89) {{/u}} sunlight, AnD FAvorABlE wAtEr CurrEnts. whEn A hEAvy rAinFAll oCCurs, minErAls AnD othEr nutriEnts ArE somEtimEs wAshED {{u}} (90) {{/u}} thE lAnD into CoAstAl wAtErs. thEsE nutriEnts CAn ContriButE to thE BrEEDing oF thE orgAnisms. thE rEsult rED tiDEs!

As A rEsult
B．As it is
C．As ExpECtED
D．As usuAl