综合类：阅读判断Rescue platform
In the aftermath of the terrorist attacks on the World Trade Center， security experts are trying to develop new ways of rescuing people from burning skyscrapers. One idea is a platform capable of flying vertically and hovering in the air like a helicopter. The platform would rise up and down alongside a skyscraper and pick up people trapped in high stories.
The idea for the vertical takeoff platform was hatched more than ten years ago by a Russian aerospace engineer， David Metreveli， who has since moved to Israel. Metrevelis design， called the Eagle， calls for two jet engines that turn four large horizontal propellers. The spinning of the propellers generates the necessary lift， or upward force， to raise the platform. The more power is supplied to the propellers， the higher the platform rises. Moving the platform sideways involves applying differing amounts of power to each propeller.
Helicopters are now used in some cases to get people out of burning buildings. Escape baskets slung from them dangle beside the building for people to climb into. Unfortunately， the baskets cannot reach every floor of a building because the ropes from which they hang become unstable beyond a certain length.
So far， Metreveli has built a small-scale model of the Eagle to test his idea. In the wake of September 11， he has been able to secure enough funding to start building a larger， 4-meter by 4-meter prototype， which he calls the Eaglet.
在世界贸易中心遭到恐怖袭击后，安全专家们正在努力寻找新方法，来从燃烧的摩天大楼上营救人们。其中的想法之一就是构建一个能够垂直升降并像直升机一样在空中盘旋的平台。该平台可沿摩天大楼上下移动，运送高楼受困人员。
十多年前，一名俄罗斯航空航天工程师David Metreveli酝酿出垂直起落平台这一想法，随后移居以色列。Metreveli的设计方案命名为“老鹰”，需用两个喷气发动机来推动四个大型水平方向旋转的螺旋推进器。螺旋推进器快速旋转，生成必要的上升力，使平台升起。供给螺旋推进器的能量越多，平台升得就越高。要使平台侧向移动，则需要给螺旋推进器添加不等的能量。
现在，人们有时还用直升机营救起火大楼中的被困人员。从直升机中抛出的救生篮在大楼旁摇摆，人们可以爬到里面去。不幸的是，由于悬挂救生篮的绳索在超出一定长度后就会非常不稳定，所以救生篮无法达到每一层楼。
目前，Metreveli已经建立起一个小型“老鹰”模型，来检测自己的构思。“9·11”事件后，Metreveli获得了足够的基金，开始构建一个较大规模的模型。该模型大小为4公尺×4公尺，他为之命名为“小鹰”。
★1). A rescue platform called the Eagle is capable of moving vertically but not sideways. -W
★2). The four propellers are fitted horizontally to the Eagle. -R
★3). With the help of jet engines， the Eagle can fly at a speed of 100 miles an hour. -N
★4). In the third paragraph， the word helicopter refers to the Eagle. -W
★5). The more jet engines are fitted to the propellers， the more people the platform can carry. -N
★6). In the wake of September 11， Mr. Metreveli has secured enough funding to build up a small-scale model of the Eagle to test his idea. -W
★7). Mr. Metreveli is designing for Israel a more advanced form of rescue platform than the Eagle or the Eaglet. -N