首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Chlorine is a mainstay in most swimming pools in the United States, and is used to eradicate bacteria. A bacteria-free pool will
Chlorine is a mainstay in most swimming pools in the United States, and is used to eradicate bacteria. A bacteria-free pool will
admin
2017-05-11
67
问题
Chlorine is a mainstay in most swimming pools in the United States, and is used to eradicate bacteria. A bacteria-free pool will usually ensure that swimmers won’t contract a serious illness if they spend time in, and possibly ingest, the water. When chlorine is added to pool water, a chemical reaction occurs whereby the chlorine breaks down into a legion of chemicals that combine to kill bacteria that may be in water. These chemicals, specifically hypochlorous acid and hypochlorite ion, eliminate bacteria by annihilating and then oxidizing the abhorrent cells. When this chemical reaction occurs, the baeteria are rendered essentially harmless. This chemical reaction doesn’t occur immediately — individual components within chlorine take varying amounts of time to interact with the bacteria, creating an almost time-release-type of kill in the pool water.
Chlorine must be regularly replenished. As they react, the hypochlorous acid and hypochlorite ion combine to create a particular acceptable pH level in the pool water. A pH is a measure of the alkalinity and acidity present; a pH value of 7 represents a neutral value, and 7. 4 is the pH value of the human tear. The pH ratio must be regularly monitored to ensure a consistent optimum ram — one usually kept within the spectrum of 7 to 8 as measured by a reliable pH measuring kit. As the chemicals in chlorine complete their reactions, they break down and are no longer effective in keeping the pool water neutralized. Additional chlorine must be added to water at specific times. Outdoor pools that are in direct sunlight need to have water added more often because the chemical reaction time for chlorine is increased and its effectiveness is reduced in these conditions. Since the hypochlorite ion is an especially potent chemical capable of fading fabrics and paint, most people are meticulous about rinsing chlorine from potentially affected areas. Although chlorine is inexpensive and widely available, some people find the bleach smell to be repugnant and the distinct aroma present at many swimming pools to be overwhelming. These people may not be able to enjoy aquatic pursuits in those pools that employ chlorine as a cleansing agent. Other people may find that inhaling chlorine at the high levels present around some pools may be difficult to tolerate. Still others may experience skin irritation after swimming in a pool containing chlorine. Although there are other chemicals and compounds available to clean swimming pools, they may be prohibitively expensive or incapable of killing all types of bacteria present in the water.
Based on the passage, which statement is probably NOT true of chlorine?
选项
A、It can be harmful if swallowed.
B、Occasional high levels in pool water arc probably not harmful.
C、It can kill most common types of pool water bacteria.
D、A pool’s size will dictate the amount needed.
答案
A
解析
排除题。文章说人们在游泳的时候很有可能呛水,因而可能会感染严重的疾病,氯气的消毒作用使人们不必担心这个问题,它对人体是无害的,所以选项A的表述错误,答案选A。
转载请注明原文地址:https://kaotiyun.com/show/zRFO777K
0
考博英语
相关试题推荐
Duringthenormaldevelopmentofself,achildisaffectedbycertaininfluentialfactors.【R1】_____.Infantsformanattachment
FrictionbetweenAmerica’smilitaryanditscivilianoverseersisnothingnew.America’s220-yearexperimentinciviliancontrol
Yoga,theancientpracticeofpostures,breathingandmeditation,isgainingalotofattentionfromthematerialworldthatits
Thecaptainperformshisdutieswithgreat_____andallthecrewbelievedthattheycangetoverthestorm.
Despitedecadesofscientificresearch,nooneyetknowshowmuchdamagehumanactivityisdoingtotheenvironment.Humansare
ToliveintheUnitedStatestodayistogainanappreciationforDahrendorf’sassertionthatsocialchangeexistseverywhere.T
Almostsincethebeginningofmankind,governmentshavebeenrecordingthenumbersoftheirpopulace.Thefirstknowncensusrepo
AWorldWithoutBooksOrMusicIfbookshadneverbeendiscovered,manwouldhavefoundsomeotherwayofrecordinghiscomm
Withhisblowsknitted,thedoctorcontemplatedthedifficultoperationhehadtoperform.
随机试题
A.输尿管结石B.前列腺增生C.盆腔肿瘤D.外伤性脾破裂E.氨基糖苷类抗生素可引起肾性肾衰竭的是()
A.前导链B.随从链C.模板链D.冈崎片段以5′→3′DNA链为模板合成的5′→3′DNA片段是
A.EB病毒B.人乳头瘤病毒C.乙肝病毒D.幽门螺旋杆菌E.丙肝病毒与宫颈癌相关的是
易引起低血糖的药物有
长期卧床的患者的站立训练应先进行
下列有关企业所得税的税收优惠规定,表述正确的是()。
甲、乙签订买卖合同后,甲向乙背书转让3万元的汇票作为价款。后乙又将该汇票背书转让给丙。如果在乙履行合同前,甲、乙协议解除合同。甲的下列行为中,符合票据法律制度规定的是()。
材料:学生张琼进入青春期后,非常关注自己的相貌。但她认为自己长相难看,不被人喜爱。看到同学聚在一块咯咯地笑,她就认为她们在笑话自己;在寝室里,若听到同学在谈论某某长得漂亮,会以为是在影射自己;上课未被老师点名发言,也会认为老师嫌自己难看不愿意点自己……所
设y1(x),y2(x)是微分方程yˊˊ+pyˊ+qy=0的解,则由y1(x),y2(x)能构成方程通解的充分条件是().
Theconceptofmanversusmachineisatleastasoldastheindustrialrevolution,butthisphenomenontendstobemostacutely
最新回复
(
0
)