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
40
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
Autism(儿童自闭症)isaseriousmentalillness,especiallyofchildren,inwhichonebecomesunabletocommunicateorformrelation
Everyoneinterviewed______(都受到了不公正的待遇).
Thepassageismainlyabout______.CPAPisausefulmachineforpeoplewithsnoringproblemsbecauseitcanhelpto______.
A、Studentsarenotrequiredtoattendregularclasslectures.B、Theprofessorvideotapesclasslecturesforreview.C、Classesar
Whyinanageofadvancedtechnology,shouldsomanypeoplestillclingtoanancientbelief?Inpartitmustbebecauseastrolo
Whyinanageofadvancedtechnology,shouldsomanypeoplestillclingtoanancientbelief?Inpartitmustbebecauseastrolo
Theconceptofpersonalchoiceinrelationtohealthbehaviorsisanimportantone.Anestimated90percentofallillnessmayb
Theconceptofpersonalchoiceinrelationtohealthbehaviorsisanimportantone.Anestimated90percentofallillnessmayb
Ms.Greenhasbeenlivingintownforonlyoneyear,yetsheseemstobe______witheveryonewhocomestothestore.
随机试题
1个月男婴,出生后13天开始呕吐,进行性加重,呈喷射样,不含胆汁。近3天尿少,未排大便,查体有中度脱水征。应首先进行的检查是
慢性乙型病毒性肝炎抗病毒治疗的目的应排除
患者,男,9岁。两颗上颌中切牙受硬物撞击,牙齿酸痛,上、下牙咬合时有不适感,牙齿未见脱位,但釉质表面有裂纹。临床及X线检查.牙根组织未见明显折断.牙周间隙稍增宽。最恰当的诊断是()
消化性溃疡最常见的并发症为
【背景资料】某公司承建城市主干道改造工程,其结构为二灰土底基层、水泥稳定碎石基层和沥青混凝土面层,工期要求当年6月份完成拆迁,12月底完成施工。由于城市道路施工干扰因素多,有较大的技术难度,项目部提前进行了施工技术准备工作。水泥稳定碎石基层施工时,项目
简述学校教育在个体身心发展中起主导作用的原因。
学生在课堂上向你提出了一个意想不到的、略有价值的问题,你不能马上作出正确的回答。这时,正确的做法是()。
对于当前的纹身现象,四个学生从各自的角度表达了他们对诸子百家思想的理解。甲说:身体天然完整,纹身就是自虐;乙说:纹身影响仪容,是低俗身份人的爱好,有身份的人不会纹身;丙说:纹身费财又费力,何必呢?简简单单不很好吗;丁
A、Every6minutes.B、Every20minutes.C、Every30minutes.D、Everyhour.B短文中提到,定时休息非常重要,最好不要长时间不休息地连续工作。之后又提到,每隔20分钟休息一次是最好的。
Asmallpopulationmaymean______.Inadevelopedcountry,peoplewillperhapsgooutofworkifthebirthrate______.
最新回复
(
0
)