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
Marjorie Rice was an unlikely candidate for the role of mathematical innovator. She had no formal education in mathematics and s
Marjorie Rice was an unlikely candidate for the role of mathematical innovator. She had no formal education in mathematics and s
admin
2013-10-11
98
问题
Marjorie Rice was an unlikely candidate for the role of mathematical innovator. She had no formal education in mathematics and save a single course required for graduation from high school in 1939. Nonetheless, in 1975 she took up a problem that professional mathematicians had twice left for dead, and showed how much life was in still.
The roblem was tessellation, or a rectangle — and fitting it together with copies of itself so that a plane is covered without any gaps or overlap. A region this plane would look rather like jigsaw puzzle whose pieces are all identical. Rice worked primarily with polygons, which consist only of straight lines. More specifically, she worked with convex polygons, in which the line joining any tow points on the polygon lies entirely within the polygon itself or on one of its edges. (A five-pointed star, for example, does not qualify as a convex polygon.)
By the time Rice took up tiling, its basic properties had been established. Obviously, any square can tile the plane, as many kitchen floors have demonstrated. Equilateral triangles are also a fairly clear-cut case. There is one other regular polygon (a polygon whose angles, and sides, are equal) that can tile the plane: hexagon. This fact was established by the ancient Greeks but had long before been exploited by honeybees in building their honeycombs.
And what of irregular polygons? As it turns out, any triangle or quadrilateral, no matter how devoid of regularity, will tile the plane. On the other hand, no convex polygon with more than six sides can do so, and the three classes of convex polygon that can were uncovered by the end of the First World War. So the only real question left by the time Marjorie Rice began her work was which convex pentagons tile the plane.
The main subject of the passage is_____.
选项
A、famous mathematicians
B、mathematical education
C、tiling the plane
D、irregular polygons
答案
C
解析
主旨题。虽然文章的开始提到了Marjorie Rice这个人,但主要是为了引出下面的内容,即“The problem was tessellation,or a rectangle…”,从第二段开始主要讲的是有关“tiling of the plane”的问题。因此C是正确的。
转载请注明原文地址:https://kaotiyun.com/show/ZnGK777K
0
专业英语四级
相关试题推荐
Notafewexcellentproposalsbythecountriesofthethirdworldhavebeen______totheUnitedNations,acceptanceofwhichwill
Theelectronicgameswouldnothave______withoutbeingingeniouslyprogrammed.
Therearetwobasicwaystoseegrowth:oneasaproduct,theotherasaprocess.Peoplehavegenerallyviewedpersonalgrowtha
Therearetwobasicwaystoseegrowth:oneasaproduct,theotherasaprocess.Peoplehavegenerallyviewedpersonalgrowtha
"Pleasepasstheturkeyanddressing."Whatdoesthissimplerequestmakeyouthinkabout?ffyouareanAmerican,youthinkabo
Wemightmarvelattheprogressmadeineveryfieldofstudy,butthemethodsoftestingaperson’sknowledgeandabilityremain
Thewarwasthemostpeacefulperiodofmylife.Thewindowofmybedroomfacedsouth-east.Ialwayswokeupwiththefirstligh
Fromchildhoodtooldage,wealluselanguageasameansofbroadeningourknowledgeofourselvesandtheworldaboutus.When
Itwouldbeverydifficultforalibrarytobewithoutdictionariesandencyclopedia;suchreferencebooksare_____.
Oneofthemanypleasuresofwatching"MadMen",atelevisiondramaabouttheadvertisingindustryintheearly1960s,isexamin
随机试题
关于PT试验国际敏感指数(ISI)的叙述错误的是
房地产项目定位的内容主要有()。[2009年考试真题]
在施工进度计划实施过程中,为缩短工程总工期,可以采用的技术措施有( )。
下列有关保证方式的表述中,不正确的是()。
机械工作时间消耗的分类中,有效工作时间包括正常负荷下和()的工作时间。
基金的监管原则包括()。
企业价值评估与项目价值评估的区别在于()。
下列环节既缴纳消费税又缴纳增值税的有()。
巴尔扎克的代表作是()。
下列行为违反《机动车驾驶证申领和使用规定》的是()。
最新回复
(
0
)