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
Less Is More It sounds all wrong—drilling holes in a piece of wood to make it more resistant to knocks. But it works because
Less Is More It sounds all wrong—drilling holes in a piece of wood to make it more resistant to knocks. But it works because
admin
2016-07-17
38
问题
Less Is More
It sounds all wrong—drilling holes in a piece of wood to make it more resistant to knocks. But it works because the energy from the blow gets distributed throughout the wood rather than focusing on one weak spot. The discovery should lead to more effective and lighter packaging materials.
Carpenters have known【C1】______centuries that some woods are tougher than others. Hickory, for example, was turned into axe handles and cartwheel spokes because it can absorb shocks without breaking. White oak, for example, is much more easily damaged, 【C2】______ it is almost as dense. Julian Vincent at Bathe University and his team were convinced the wood’s internal structure could explain the differences.
Many trees have tubular vessels that run【C3】______the trunk and carry water to the leaves. In oak they are large, and arranged in narrow bands, but in hickory they are smaller, and more evenly distributed. The researchers【C4】______this layout might distribute a blow’s energy throughout the wood, soaking up a bigger hit. To test the idea, they drilled holes 0. 65 millimetres across into a block of spruce, a wood with 【C5】______vessels, and found that 【C6】______withstood a harder knock.【C7】______when there were more than about 30 holes per square centimeter did the wood’s performance drop off.
A uniform substance doesn’t cope well with knocks because only a small proportion of the material is actually【C8】______. All the energy from the blow goes towards breaking the material in one or two places, but often the pieces left【C9】______are pristine(未经破坏的).
But instead of the energy being concentrated in one place, the holes provide many weak spots that all absorb energy as they break, says Vincent. "You are controlling the places【C10】______ the wood breaks, and it can then absorb more【C11】______, more safely. "
The researchers believe the principle could be applied to any material—【C12】______example , to manufacture lighter and more protective packaging. It could【C13】______be used in car bumpers, crash barriers and armor for military vehicles, says Ulrike Wegst, 【C14】______ the Max Plank Institute for Mental Research in Stuttgart. But she emphasizes that you’d 【C15】______to design the substance with the direction of force in mind. "The direction of loading is crucial, " she says.
【C7】
选项
A、If
B、Just
C、Only
D、Rarely
答案
C
解析
空格所在的句子是一个倒装句,所以应该选only,only when引起主句中主语和助动词(did)倒置。整个句子的意思是:只有当每平方厘米超过30个孔时,木头抵御敲打的表现才变差。故选C。
转载请注明原文地址:https://kaotiyun.com/show/CILd777K
本试题收录于:
职称英语理工类B级题库职称英语分类
0
职称英语理工类B级
职称英语
相关试题推荐
NaturalMedicinesSinceearliestdays,humanshaveusedsomekindsofmedicines.Weknowthisbecausehumanshavesurvived.
NaturalMedicinesSinceearliestdays,humanshaveusedsomekindsofmedicines.Weknowthisbecausehumanshavesurvived.
Themanagergotangryjustbecausehissecretarywastenminuteslate.
ScienceandTechnologyThereisadifferencebetweenscienceandtechnology.【B1】______Sciencehastodowithdiscoveringth
CulturalDifferencesPeoplefromdifferentculturessometimesdothingsthatmakeeachotheruncomfortable,sometimeswithou
"Heisexemptedfrommilitaryservice,becauseofhisbadsight."
TheboysoldgoodsfromdoortodoorbecauseAmongotherthings,thestoryshowsthat
TheGeneIndustryMajorcompaniesandalreadyinpursuitofcommercialapplicationsofthenewbiology.Theydreamofplacing
Inordertoimproveourstandardofliving,wehavetoaccelerateproduction.
随机试题
固定式龙门铣床水平铣头在立柱上垂直移动(W轴线)对垂直铣头移动(Y轴线)的垂直度,在500mm测量长度上,公差为()mm。
男性,12岁,五年级学生,学习成绩不好,上课注意力不集中,坐不住,一会捅捅前座同学,一会又和后座同学讲话,上体育课不好好排队,还大声嚷嚷,经常不能完成作业,甚至将作业本遗失在学校。该患儿社交障碍的相关因素()
贫血的治疗原则首先是
下列哪种有机粉尘不会引起肺部病变
治疗乳牙的目的
下列选项所述的专项方案,可由专业工程分包单位编制的是()
背景某施工单位通过公开招标中标某工程,与业主签订的承包合同部分内容有:(1)工程合同总价2100万元,工程价款采用调值公式动态结算;该工程的人工费可调,占工程价款的35%;材料有4种可调:材料1占5%,材料2占15%,材料3占15%,材
简述高等教育教学过程中应遵循的主要原则。
设向量组α1=(a,2,10)T,α2=(-2,1,5)T,α3=(-1,1,4)T,β=(1,b,c)T.试问:当a,b,c满足什么条件时,(1)β可由3线性表出,且表示唯一?(2)β不能由α1,α2,α3线性表出?(3)β可由α1,α
Americaneconomistsoncespoofeduniversityeducationastheonlyindustryinwhichthosewhoconsumeitsproductdonotpurchas
最新回复
(
0
)