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giant structures-it is an impossible task to select the most amazing wonders of the modem world since every year more wonderful_constructions appear. here are three giant structures which are worthy of our admiration although they may have been surpassed by some more recent wonders.the petronas twin towers-the petronas towers were the tallest buildings in the world when they were completed in 1999. with a height_ of 452 metres, the tall twin towers, like two thin pencils, dominate the city of kuala lumpur. at the 41st floor, the towers are linked by a bridge, symbolizing a gateway to the city. the american architect cesar pelli designed the skyscrapers.the miuau bridge-the millau bridge was opened in 2004 in the tam valley,in southern france. _at_ the time it was built,it was the worlds highest bridge, _reaching_ over 340m at the highest point. the bridge is described as one of the most amazingly beautiful bridges in the world. it was built to _relieve millaus congestion problems. the congestion was then caused by traffic passing from paris to barcelona in spain. the bridge was built to withstand the most extreme seismic and climatic conditions. besides, it is guaranteed for 120 years!the itaipu dam-the itaipu hydroelectric power plant is one of the largest constructions of its kind in the world. it consists of a series of dams across the river parana, which_ forms a natural border between brazil and paraguay. started in 1975 and taking 16 years to complete, the construction was carried out as a joint project between the two countries. the dam is well-known for both its electricity output and its size. in 1995 it produced 78% of paraguays and 25% of brazils _energy needs. in its construction, the amount of iron and steel used was equivalent to over 300 eiffel towers. it is a truly amazing wonder of engineering.why india needs its dying vulturesthe vultures in question may look ugly and threatening, but the sudden sharp decline in three species of indias vultures is producing alarm rather than celebration, and it presents the world with a new kind of environmental problem the dramatic decline in vulture numbers is causing widespread disruption to people living in the same areas as the birds . it is also causing serious public health problems across the indian sub-continent.while their reputation and appearance may be unpleasant to many indians,vultures have long played a very important role in keeping towns and villages all over india clean. it is because they feed on dead cows. in india, cows are sacred animals and are _traditionally left in the open when they die in their thousands upon thousands every year.the disappearance of the vultures has led to an explosion in the numbers of wild dogs feeding on the remains of these dead animals. there are fears that rabies may increase as a result. and this terrifying disease may ultimately affect humans in the region, since wild dogs are its main carriers. rabies could also spread to other animal species, causing an even greater problem in the future.the need for action is urgent, so an emergency project has been launched to find a solution to this serious vulture problem. scientists are trying to identify the disease causing the birds,deaths and, if possible, develop a cure.large-scale vulture deaths were first noticed at the end of the 1980s in india. a population survey at that time showed that the three species of vultures had declined by over 90 per cent. all three species are now listed as “critically endangered”. as most vultures lay only single eggs and take about five years to reach maturity, reversing their population decline will be a long and difficult exercise.13- better solar energy systems: more heat, more light -solar photovoltaic thermal energy systems, or pvts, generate both heat and electricity, but until now they havent been very good at the heat-generating part compared to a stand-alone solar thermal collector. thats because they operate at low temperatures to cool crystalline silicon solar cells, which lets the silicon generate more electricity but isnt a very efficient way to gather heat.thats a problem of economics . good solar hot-water systems can harvest much more energy than a solar-electric system at a substantially lower cost. and it,s also a space problem:photovoltaic cells can take up all the space on the roof, leaving little room for thermal applications.in a pair of studies, joshua pearce, an associate professor of materials science and engineering, has devised a solution in the form of a better pvt made with a different kind of silicon. his research collaborators are kunal girotra from thinsilicon in california and michael pathak and stephen harrison from queens university, canada.most solar panels are made with crystalline silicon,but you can also make solar cells out of amorphous silicon, commonly known as thin-film silicon. they dont create as much electricity, but they are lighter, flexible, and cheaper. and, because they require much less silicon, they have a greener footprint. unfortunately,thin-film silicon solar cells are vulnerable to some bad-news physics in the form of the staebler-wronski effect.“that means that their efficiency drops when you expose them to light pretty much the worst possible effect for a solar cell,” pearce explains,which is one of the reasons thin- film solar panels make up only a small fraction of the market.however, pearce and his team found a way to engineer around the staebler-wronski effect by incorporating thin-film silicon in a new type of pvt. you dont have to cool down thin-film silicon to make it work. in fact,pearces group discovered that by heating it to solar-thermal operating temperatures,near the boiling point of water, they could make thicker cells that largely overcame the staebler-wronski effect. when they applied the thin-film silicon directly to a solar thermal energy _collector_ , they also found that by baking the cell once a day,they boosted the solar cells electrical efficiency by over 10 percent.研究人员发现人类开始直立行走的原因我们大多数人每天都走路而且手里搬着东西。这样的活动看似太简单,大多数人没有疑问。但是一个国际研究者(包括乔治华盛顿大学哥伦比亚艺术与科学学院的richmond博士)团队已经发现了人类直立行走可能源于数百万年以前适应搬运稀有的、高质量的资源。这些来自美国、英国、日本和葡萄牙的研究者研究了当代黑猩猩争抢食物时的行为特征,试图对什么样的生态环境竟然导致大猿(一种我们与现存的黑猩猩一样的600万年前的祖先)直立行走作出解释。“这些黑猩猩居住的生态环境和我们最早的祖先开始直立行走时是相同的,” richmond博士说。研究结果显示,当黑猩猩需要独占一种资源时,它们就从四肢行走转换为直立行走。由于直立行走可以解放它们的双手,这使得它们能搬更多的东西。久而久之,双足活动的强烈爆发可能导致了解剖学上的变化,因此这种变化也就成为自然选择的主题,在那种情况下,对食物或其他 资源的争夺是十分激烈的。有两项研究是在几内亚完成的。第一项研究是在京都大学博苏森林的一块天然空地“室外实验室”进行的。研究者们允许森林里的黑猩猩能得到两种不同的坚果,一种叫油棕榈坚果,自然界随处可见,一种叫可乐果,自然环境中不常见。人们监控黑猩猩在下列三种情形下的行为:(a)只有油棕榈坚果;(b)只有少量的可乐果,大多数是油棕榈坚果;(c)大多数是可乐果,少数是油棕榈坚果。当稀有的可乐果数量很少时,黑猩猩一次就会拿得多。同样,当大部分是可乐果时,黑猩猩对油棕榈坚果根本视而不见。黑猩猩认为可乐果才是珍贵的资源,并为得到可乐果激烈竞争。处于这种激烈竞争的环境中,黑猩猩直立行走的频率增加了四倍。很显然,双足行走可以使它们拿走更多的稀有资源,而且,为了尽可能地一口气多拿,它们积极利用可用到的任何方法,甚至嘴巴。第二项研究是在牛津布鲁克斯大学的kimberley hockings进行的。该研究历时14个月,主题是博苏的黑猩猩抢劫粮食,场景是它们不得不为稀有和不可预知的资源竞争。在这项研究中,黑猩猩35%的活动是直立行走。而这一次研究再一次证实了黑猩猩的直立行走与它们试图一次搬走尽可能多的东西有关。1.which of the following statements is not true according to the first two paragraphs?- a many people question the simple human activities of walking and carrying items.2.dr. richmond conducted the experiment with the purpose of finding- b what made our ancestors walk upright.3.kyoto, universitys study discovered that chimpanzees.- c liked coula nuts better than oil palm nuts.4.why did the chimpanzees walk on two limbs during kyoto universitys experiment?- d because they wanted to carry more nuts with two free limbs.5.what can we infer from the reading passage?- d human walking on two legs developed as a means of survival.音乐机器人伴侣提升音乐欣赏体验shimi是由佐治亚理工大学音乐技术中心研发的一款音乐伴侣。它可以根据听者的反馈推荐合乎节拍的歌曲、舞蹈;并且不断播放音乐。这款髙1英尺的机器人是由智能手机系统支持的,因此被标榜为“一个可以互动的音乐朋友”。gil weinberg教授是该机器人的发明者,他解释说:“shimi设计的宗旨是改变人们欣赏音乐、认识音乐的方式。”他将在今年6月27日在旧金山的谷歌i/o大会上展示这款机器人。一个由三个机器人组成的乐队将为来宾演奏,并伴随音乐起舞。而音乐是根据不同的运动形式编制的。shimi实际上是一个扩充基座,它的“大脑”由安卓手机控制。一旦连接上,机器人便从用户的移动装置获得传感和音乐生成能力。换言之,只要有应用程序,机器人便能使用。例如,通过手机的照相机和辨认脸型的软件,shimi就能在房间周围跟踪到听众,然后安置好它的“耳朵”或扬声器,以确保输送最佳声音。另外一种识别特征是基于节奏和速度。如果用户打出某个(音乐)拍子,shimi会对此进行分析,然后浏览手机的音乐库,并立即演奏最符合要求的音乐。一旦音乐响起来,shimi就随韵律起舞。“许多人认为机器人受到程序指令的限制,而shiini给我们展示了机器人可以具有创造力和与人交互的能力。”音乐技术博士研究生mason bret
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