问题 单项选择题

大跨度推力式钢拱桥一般可以比同跨度梁式桥少用钢材(),且外表美观。

A、5%~10%

B、10%~15%

C、15%~20%

D、20%~25%

答案

参考答案:C

单项选择题

It is hard to box against a southpaw, as Apollo Creed found out when he fought Rocky Balboa in the first of an interminable series of movies. While "Rocky" is fiction, the strategic advantage of being left-handed in a fight is very real, simply because most right-handed people have little experience of fighting left-handers, but not vice versa. And the same competitive advantage is enjoyed by left-handers in other sports, such as tennis and cricket.

The orthodox view of human handedness is that it is connected to the bilateral specialization of the brain that has concentrated language-processing functions on the left side of that organ. Because, long ago in the evolutionary past, an ancestor of humans (and all other vertebrate animals ) underwent a contortion that twisted its head around 180° relative to its body, the left side of the brain controls the right side of the body, and vice versa. In humans, the left brain (and thus the right body ) is usually dominant. And on average, left-handers are smaller and lighter than right-handers. That should put them at an evolutionary disadvantage. Sporting advantage notwithstanding, therefore, the existence of left-handedness poses a problem for biologists. But Charlotte Faurie and Michel Raymond, of the University of Montpellier Ⅱ, in France, think they know the answer. As they report in the Proceedings of the Royal Society, there is a clue in the advantage seen in boxing.

As any schoolboy could tell you, winning fights enhances your status. If, in prehistory, this translated into increased reproductive success, it might have been enough to maintain a certain proportion of left-handers in the population, by balancing the costs of being left- handed with the advantages gained in fighting. If that is true, then there will be a higher proportion of left-handers in societies with higher levels of violence, since the advantages of being left-handed will be enhanced in such societies. Dr Faurie and Dr Raymond set out to test this hypothesis.

Fighting in modern societies often involves the use of technology, notably firearms, that is unlikely to give any advantage to left-handers. So Dr Faurie and Dr Raymond decided to confine their investigation to the proportion of left-handers and the level of violence (by number of homicides) in traditional societies.

By trawling the literature, checking with police departments, and even going out into the field and asking people, the two researchers found that the proportion of left-handers in a traditional society is, indeed, correlated with its homicide rate. One of the highest proportions of left-handers, for example, was found among the Yanomamo of South America. Raiding and warfare are central to Yanomamo culture. The murder rate is 4 per 1000 inhabitants per year (compared with, for example, 0.068 in New York). And, according to Dr Faurie and Dr Raymond, 22.6% of Yanomamo are left-handed. In contrast, Dioula-speaking people of Burkina Faso in West Africa are virtual pacifists. There are only 0.013 murders per 1000 inhabitants among them and only 3.4% of the population is left- handed.

While there is no suggestion that left-handed people are more violent than the right- handed, it looks as though they are more successfully violent. Perhaps that helps to explain the double meaning of the word "sinister".

Which of the following might be the best title for the passage()

A. Left-handedness in Traditional Society

B. Left-handedness VS Right-handedness

C. Left-handedness and Violence

D. The advantage of Left-handedness in Boxing

单项选择题

阅读以下文字,完成以下问题。
微晶玻璃是一种我国刚刚开发的新型的建筑材料,它的学名叫做玻璃陶瓷。微晶玻璃和我们常见的玻璃看起来不大相同。它具有玻璃和陶瓷的双重特性,普通玻璃内部的原子排列是没有规则的,这也是玻璃易碎的原因之一。而微晶玻璃像陶瓷一样,由品体组成,也就是说,它的原子排列是有规律的。所以,微晶玻璃比陶瓷的亮度高,比玻璃韧性强。
现在,我们做一个微晶玻璃与天然石材的对比实验。我们把墨水分别倒在大理石和微晶玻璃上,稍等片刻,微晶玻璃上的墨汁可以轻易的擦掉,而大理石上的墨迹却留了下来。这是为什么呢大理石、花岗岩等天然石材表面粗糙,可以藏污纳垢,微晶玻璃就没有这种问题。大家都知道,大理石的主要成分是碳酸钙,用它做成建筑物,很容易与空气中的水和二氧化碳发生化学反应,这就是大理石建筑物日久变色的原因,而微晶玻璃几乎不与空气发生反应,所以可以历久长新。
专家介绍说,这项发明的突破点主要有两个,分别是原料的配比和工艺的设计。其中,工艺的设计是技术的关键。置备微晶玻璃首先要把原材料按照比例配好,放到窑炉里烧熔,等全部熔化之后,把溶液倒在冰冷的铁板上,这叫做淬火。淬火之后,原料已经成一块品莹的玻璃,这一步是烧结的过程。现在,我们把玻璃捣碎,装入模具,抹平,再次放入窑炉,这次煅烧使它的原子排列规则化,是从普通玻璃到微晶玻璃的过程。
一般的废渣土中都含有制作微晶玻璃的大多数成分,我们通过电脑检测,确定现有原料的化学组成,添加所缺部分,大大降低了成本。微晶玻璃利用废渣、废土做原料,有利于环境治理,可以变废为宝,与各地环保工作同步进行。

技术的关键是( )。

A.工艺

B.工艺的设计

C.成分

D.材料