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
Although many of us may feel air-conditioners bring relief from hot, humid or polluted outside air, they pose many potential hea
Although many of us may feel air-conditioners bring relief from hot, humid or polluted outside air, they pose many potential hea
admin
2016-09-21
34
问题
Although many of us may feel air-conditioners bring relief from hot, humid or polluted outside air, they pose many potential health hazards. Much research has looked at how the movement of air inside a closed environment—such as an office building—can spread disease or expose people in the building to harmful chemicals.
One of the more widely publicized dangers is that of Legionnaire’s disease, which was first recognized in the 1970s. This was found to have affected people in buildings with air-conditioning systems in which warm air pumped out of the system’s cooling towers was somehow sucked back into the air intake(通风口), in most cases due to poor design. The warm air, filled with bacteria, was combined with cooled, conditioned air and was then circulated around various parts of the building. Studies showed that even people outside such buildings were at risk if they walked past air exhaust pipes.
Large air-conditioning systems add water to the air they circulate by means of humidifiers(湿度调节器). In older systems, the water used for this process is kept in special reservoirs, the bottoms of which provide breeding grounds for bacteria which can find their way into the ventilation(通风)system. The risk to human health from this situation has been highlighted by the fact that the immune systems of approximately half of workers in air-conditioned office buildings have developed the ability to fight off the organisms found at the bottom of system reservoirs. But chemicals called "biocides" are added to reservoirs to make them germ-free, and they are dangerous in their own right in sufficient quantities, as they often contain compounds strongly linked to cancers.
Finally, it should be pointed out that the artificial climatic environment created by air-conditioners can also affect us. In a natural environment, whether indoor or outdoor, there are small variations in temperature and humidity. Indeed, the human body has long been accustomed to these normal changes. In an air-conditioned living or work environment, however, body temperatures remain well under 37℃, our normal temperature. This leads to a weakened immune system and thus greater exposure to diseases such as colds and flu.
The last paragraph implies that our immune system can be weakened when _____.
选项
A、we live in an artificial climatic environment
B、there are variations in temperature and humidity
C、our body temperatures often remain not high enough
D、we are often exposed to diseases such as colds and flu
答案
C
解析
本题考查代词的理解。解题的关键在于理解最后一句中的This是指上一句所说的情况。A中所说的人造环境不是使免疫系统变弱的必然条件。B是保持免疫系统健康的条件。D是免疫系统变弱后的影响。
转载请注明原文地址:https://kaotiyun.com/show/WNY7777K
0
大学英语四级
相关试题推荐
Friendsplayanimportantpartinourlives.Andalthoughwetaketheactoffriendshipforgranted,weoftendon’t【B1】______und
Friendsplayanimportantpartinourlives.Andalthoughwetaketheactoffriendshipforgranted,weoftendon’t【B1】______und
Friendsplayanimportantpartinourlives.Andalthoughwetaketheactoffriendshipforgranted,weoftendon’t【B1】______und
A、Readthearticlewhileshewaitsinline.B、Havehercopiesmadeoutsidethelibrary.C、Useadifferentmachinetomakeherco
Mostpeoplewouldagreethat,althoughourageexceedsallpreviousagesinknowledge,therehasbeennocorrelativeincreasein
Mostpeoplewouldagreethat,althoughourageexceedsallpreviousagesinknowledge,therehasbeennocorrelativeincreasein
A、Thebenefitsofstrongbusinesscompetition.B、Aproposaltolowerthecostofproduction.C、Complaintsabouttheexpenseofm
A、Hewillbeathisopponentsbyafewvotes.B、He’sthemostpromisingcandidatefortheschoolboard.C、Hewillbesupportedby
InordertohosttheOlympics,acitymustsubmitaproposaltotheIOC.Afterallproposalshavebeensubmitted,theIOCvotes.
随机试题
陶渊明的诗质朴自然,冲和平淡,“开千古平淡之宗”。()
代表药物安全性的指标是
依据《刑法》的相关规定,下列关于数罪并罚的做法与说法,哪些是错误的?
中国甲公司(卖方)与某国乙公司签订了国际货物买卖合同,规定采用信用证方式付款,由设在中国境内的丙银行通知并保兑。信用证开立之后,甲公司在货物已经装运,并准备将有关单据交银行议付时,接到丙银行通知,称开证行已宣告破产,丙银行将不承担对该信用证的议付或付款责任
通货和活期存款都有一定的或较高的收益率。()
()的目的是增加顾客和其他相关方满意的机会。
期权合约会涉及出售方和购买方双方,期权是一种“特权”,是因为()。
张某与王某于2010年登记结婚,2012年,张某购买商品房一套,并以个人名义办理了产权登记。2013年,由于张某不育,张某与王某共同与某医院签订了人工生殖协议书,对王某实施了人工授孕。王某怀孕期间,张某体检得知自己患有恶性肿瘤,将不久于人世,便向王
为贬低他人而取绰号的行为侵犯了公民的()。
2013年7月20日,中国人民银行决定全面放开金融机构贷款利率管制,取消贷款利率0.7倍的下限,由金融机构根据商业原则自主确定贷款利率水平,至此我国全面放开了贷款利率管制。试分析中国人民银行这一货币政策调整的经济背景及政策意义。
最新回复
(
0
)