Thestudentswerehavingtheirchemistry(化学）class.MissLiwastellingthestudentswhatwaterwaslike.Afterthat,sheaskedherstudents,"What'swater?"Noonespokeforafewminutes.MissLiaskedagain,"Whydon'tyouanswermyquestion?Didn'tItellouwhatwaterislike?" 　　Justthenastudentputuphishandandsaid,"MissLi,youtoldusthatwaterhasnocolorandnosmell.However,wheretofindsuchkindofwater?Thewaterintheriverbehindmyhouseisalwaysblackandithasabadsmell."Mostofthestudentsagreedwithhim. 　　"I'msorry,children."saidtheteacher,"Ourwaterisgettingdirtieranddirtier.That'saproblem." 　　学生们正在上化学课.李老师正在告诉他们水是什么样子的.然后,她问他的学生们,什么是水?一时间没有人说话.李老师又问了一遍,为什么你们不回答我的问题?难道我没有告诉你们水是什么样的么? 　　然后又一个学生举起了手说,李老师,你告诉我们水是无色无味的,然而,上哪去找这样的水呢?我家门前江里的水总是黑的还有一股难闻的味道.许多学生都同意她的说法. 　　对不起,孩子们.老师说,我们的水正在变得越来越脏.那的确是个问题 　　LosAngeles 　　LosAngeleswasfoundedin1781.With3.5millionpeopleitisnowthebiggestcityinCaliforniaandthesecondlargestcityintheUnitedStates.Itisfamousforitsmodernhighways,itsmoviestars,anditssmog.Whenthecityisreallysmoggy,youcan’tseethenearbymountains.Theweatherisusuallydryandwarm.Visitorsliketogotothefilmstudios(摄影棚)andtodrivealongHollywoodStreet.Therearemanygoodbeachesnearthecity,andLosAngelesisalsoclosetoDisneyland. 　　Taipei 　　SincethefoundingofTaipeiinthe18thcentury,thecityhasgrowntoapopulationof2.3million.Taipeiisanexcitingcity,buttheweatherishumid(潮湿)andnotalwayspleasant. 　　It’salsoaverybusycity,andthestreetsarealwaysfullofpeople.Thereisanexcellentmuseumthatmanypeoplevisit.Taipeiisquiteanexpensivecity,butnotmoreexpensivethansomeneighboringcitiessuchasHongKongandTokyo.SomoreandmoretravelersgotoTaipeitoshop.