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
All competitive ski and snowboarding events now take place largely on man-made snow. Unlike its natural counterpart, the machine
All competitive ski and snowboarding events now take place largely on man-made snow. Unlike its natural counterpart, the machine
admin
2012-08-05
22
问题
All competitive ski and snowboarding events now take place largely on man-made snow. Unlike its natural counterpart, the machine-made white stuff can be carefully tweaked to make a more durable and consistent surface: one perfect for record-breaking attempts. Snow-making equipment is viewed as essential in most ski areas to guarantee coverage throughout the season. Nowadays, "natural snow is a bonus," says Rich Brown of snow-making technology company York Snow in Victor, New York.
The snow "cannons" or "guns" that manufacture snow mimic the natural formation of snowflakes. Snpw machines typically force pressurized water through a nozzle (喷嘴), breaking it into a mist of tiny droplets, and then use compressed air or fans to blast them into the air. As the droplets cool, the molecules line and crystallize into ice particles. The art to snow-making is adjusting the water and air to ensure that the water drops are small enough and sent far enough that they will freeze before they hit the ground. If the air temperature is quite high, for example, dropping the water content and upping the air would create smaller particles that are more likely to freeze. Snow-making machines also frequently incorporate nucleating agents (成核剂) in the water: small quantities of materials such as bacterial protein, on to which the water molecules attach and freeze. By triggering freezing, these agents raise the temperature at which snow can be made.
Many resorts now use sophisticated computer systems that automatically adjust the air and water output from snow machines based on air temperature, humidity and wind, says Brown. For race courses, experts adjust man-made snow to create a tough, fast and icy course rather than a powdery one. A ski course is also heavily groomed and often intentionally flooded to create patches of ice; these factors generally determine the speed of a race.
Snow manufacturing is in great demand. Some predict that the need for snow will rocket with the warming effects of climate change, which are already pushing snow lines up the Alps. But this comes with environmental costs, says Michel Revaz, of the International Commission for Protection of the Alps (ICPRA). Making snow chews up energy and water, and can rob rivers and creeks in the surrounding ecosystems. One way to conserve the mountain environment, Revaz says, would be to reuse winter sports competition facilities rather than building new ones.
The mechanism of snow machines imitates______.
选项
答案
the natural formation of snowflakes
解析
同义转述题。本题考查制造人造雪的机械原理。定位句指出,雪炮(枪)是模仿了雪花形成的自然原理。题干中的imitates是原文mimic的同义转述;而snow machines指原文中的snow“canons”or“guns”,故答案为the natural formation of snowflakes。
转载请注明原文地址:https://kaotiyun.com/show/4sb7777K
0
大学英语六级
相关试题推荐
A、Dead.B、Worse.C、Better.D、Unclear.C
A、Themanispleasedtoworkforthewoman.B、Themanhoistedthesuitcasewithoutmucheffort.C、Thewomandoesn’tknowwheret
Ontheweddingparty,everyoneiswondering______(为什么他穿牛仔服不穿套装).
A、Collegeenrollmentincreasesitscoverage.B、Topuniversitiesbecomeincreasinglycompetitive.C、Universitiesbecomeselective
Manypeoplelikethegiganticwhales.Humansympathy【C1】______whalesisonlynaturalofallthecreaturesinthesea.【C2】___
Whyinanageofadvancedtechnology,shouldsomanypeoplestillclingtoanancientbelief?Inpartitmustbebecauseastrolo
Theconceptofpersonalchoiceinrelationtohealthbehaviorsisanimportantone.Anestimated90percentofallillnessmayb
Theconceptofpersonalchoiceinrelationtohealthbehaviorsisanimportantone.Anestimated90percentofallillnessmayb
Theconceptofpersonalchoiceinrelationtohealthbehaviorsisanimportantone.Anestimated90percentofallillnessmayb
随机试题
简述伸展练习计划的内容。
对外开放的理论核心是要正确理解()的关系。
大腹痛者,多属( )。
属于蒙药理论的有()。
下列哪些案件由人民检察院直接受理?()
土地的经济特性有()。
某项目进口一批生产设备,FOB价为650万元(人民币价),CIF价为830万元,银行财务费率为0.5%,外贸手续费率为1.5%,关税税率为20%,增值税率为17%。该批设备无消费税和海关监管手续费,则该批进口设备的抵岸价为( )万元。
甲发现用银行卡在乙商场购买的一台电视机存在质量问题,遂要求乙商场退货。乙商场在办理退货手续时以现金方式退还给甲支付的价款,并将退货单送交收单银行。乙商场的行为不符合银行卡业务管理的规定。()
2020年1月1日甲公司出售30%的乙公司股权,取得价款2100万元,出售这部分股权后,甲公司还持有乙公司40%的股权,不能再对乙公司实施控制,改按权益法核算相关股权投资。乙公司可辨认净资产在处置当日的公允价值为9800万元,账面价值为9500万元。
下列关于通过数据通信线路连接到ISP的叙述中,错误的是
最新回复
(
0
)