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
自考
In our day of the automobile and paved highway few people ever encounter quicksand(流沙). Yet quicksand is still common in many pa
In our day of the automobile and paved highway few people ever encounter quicksand(流沙). Yet quicksand is still common in many pa
admin
2011-01-31
103
问题
In our day of the automobile and paved highway few people ever encounter quicksand(流沙). Yet quicksand is still common in many pans of the country. It may be more dangerous for being less familiar.
Quicksand is usually found along the shores and in the beds of rivers. It is simply sand saturated(使饱和)with water from beneath,as from a spring. The water flowing into the sand separates the grains. The suspended grains give rather easily and a heavy object placed on the surface is likely to sink. How fast it sinks depends on its weight and surface area.
How does one detect quicksand? It cannot be done by the eye alone,since sand which looks firm may suddenly collapse and trap anyone who ventures out on it. The only way to be sure is to test the sand before walking on it. For test a probing(探索)pole or long stick should be used. If the pole sinks more than six inches,the sand is probably quicksand.
A traveler who stumbles into quicksand will soon sink to the depth of his knees. If he stands still or struggles wildly,he will sink even further. He should at once lie on his back and stretch out his arms. Contrary to popular notion,quicksand does not suck objects down,and will support more weight than water alone. While the trapped person“floats”on the surface of the sand,rescuers should build a platform with boards or branches. Then they can pull him out slowly.
If the trapped person is alone,he can rescue himself. When he is in the floating position,he should begin rolling toward solid ground. Rolling is the only way of getting free. It should be done with frequent rests,so that the trapped person does not tire himself. When he reaches solid ground,he should swing his legs to safety,and quickly scramble out of the quicksand.
According to the passage,quicksand is usually found______.
选项
A、on hillsides
B、far inland
C、near water
D、on prairies
答案
C
解析
见第二段第一句话,流沙通常存在于沿岸边和河床上。选项C最为接近。
转载请注明原文地址:https://www.kaotiyun.com/show/yVAR777K
本试题收录于:
英语(二)题库公共课分类
0
英语(二)
公共课
相关试题推荐
Americansareaveryenergeticandmobilepeople,alwaysontherun,rushingfromoneappointmenttoanother,fromaPTA(Parent-Tea
Weallknowthathumansaredamagingtheenvironment,butwhatcanwedoaboutit?Somepeoplearetryingtodotheirbittobemo
ImethimontheInternetandwechattedforseveralmonths.EverytimeIsuggestedwemeetinperson,hewouldcomeupwithane
SomepeoplemightthinkthatFather’sDaywasestablishedasaholidaytohelpgreetingcardcompaniessellmorecards.However,
Inaquiet,darkenedlectureroom,youbeginafrustratingfightagainstfatigue.Theoverheadprojectorhums,andyoucannotconce
Thearticlesuggeststhatwhenaperson______underunusualstresshe______especiallycarefultohaveawellbalanceddiet.
______theywillnotcometojoinus,wehavetochangeourplan.
UnderstandwhatJetLagis,andhowacarefuldietcan______(minimum)itsworsteffects,andyourflightswillbelessstressful.
ScienceFiction1Amongstthemostpopularbooksbeingwrittentodayarethosewhichareusuallyclassifiedasscienceficti
A.WashingtonwenttostudybridgesB.toexpressherthanksC.WashingtontookoverthejobD.tobuildthebridgeE.Emilybeg
随机试题
含50%乙醇和50%水的溶液,用普通蒸馏的方法不能获得98%的乙醇水溶液。()
简述专利法不予保护的对象。
为什么说生产力和生产关系之间的矛盾、经济基础上层建筑之间的矛盾是人类社会的基本矛盾?
关于女性生殖器官的自然防御功能,下列说法中正确的是()。
下列哪项是血源性肺脓肿最常见的病原菌
下列关于增值税规定,表述不正确的是,()。
以下属于重庆机场的有()。
p,q,r,s为正实数,且已知p2+q2=3,pr+sq=4,则r2+s2的最小值为。()
A、 B、 C、 D、 C公比为的等比数列,下一项为=(1)。
香蕉“巴拿马病”学名为香蕉枯萎病。因为巴拿马病是植物病原物引染起的,树的维管束内繁殖,它只感染香蕉树,香蕉树不会结果,结果的香蕉树肯定是不染病的。香蕉枯萎病与食用香蕉的安全性没有任何关联。通过选育优良品种、推行标产、综合应用各种病虫害防治措施整套技术,可控
最新回复
(
0
)