A California company has unveiled a tiny flying drone

    A California company that makes unmanned drone aircraft for the U.S. military has unveiled a tiny flying drone that looks like a hummingbird¹(蜂鸟).  The airborne spy is part of a new kind of military technology that also has civilian² uses.
    Several years in development, the so-called nano-hummingbird is a smaller and more maneuverable version of drones now used by the U.S. military in Iraq and Afghanistan(阿富汗).  It looks like a real hummingbird with quickly flapping wings, and just like the real bird, can hover³ in mid-air and fly backwards⁴.
    The company that created it, AeroVironment, develops and tests drones outside Los Angeles.  They give observers an eye in the sky, and spot objects and track people on the ground.
    The tiny bird-like drone has a camera and transmitter and a wingspan of just 17 centimeters.   It is operated remotely and flies by moving its wings, says project manager Matthew Keennon.
    "It's being manipulated and controlled to allow the forward and backward flight, the rotation⁵ and also the side-to-side flight.  And all that's happening by just changing the curvature and the shape and different aspects of the wing movement at a very high speed," noted⁶ Keennon.
    The tiny drone is still experimental.  The challenge and the funding came from the Defense⁷ Advanced Research Projects Agency(代理,中介), which asked for an airborne vehicle that would mimic⁸ something in nature.
    Project manager Keennon says the challenge was huge and the work has been exciting.
    "Because every time we made an improvement, got better, we were just so amazed," added Keennon.
    While the company is developing some of the world's smallest drones, it is also testing one of the largest.  Called Global Observer, this unmanned craft is thin and sleek⁹ but has a wingspan almost equal to a Boeing 747.  It is powered by liquid hydrogen and can hover in the stratosphere, says AeroViroment's Steven Gitlin.
    "And it's designed to fly for up to seven days at a time at about 65,000 feet [20,000 meters] altitude and carry a payload that either helps somebody see what they want to see or relays communication from one point to another," explained Gitlin.
    The company spokesman says airborne drones are used for military surveillance, but also have civilian uses.
    "Applications like first response, search and rescue, law enforcement, border security, even facility security and event security - anywhere a bird's-eye view in the sky in real time can help somebody do their job more effectively and more safely is a potential application for this technology," added Gitlin.
    And the new nano-hummingbird will go places that larger drones cannot.
    AeroVironment engineers say the device will still be in development for the next few years, and may not reach the market in its present form.  But they say the technology developed for the device will be used in future products.(本文由在线英语听力室整理编辑)

1 hummingbird   

n.蜂鸟

参考例句：

• The hummingbird perches on a twig of the hawthorn.小蜂鸟栖在山楂树枝上。
• The hummingbird is the only bird that can fly backward.蜂鸟是唯一能倒退向后飞的鸟。

2 civilian   

adj.平民的，民用的，民众的

参考例句：

• There is no reliable information about civilian casualties.关于平民的伤亡还没有确凿的信息。
• He resigned his commission to take up a civilian job.他辞去军职而从事平民工作。

3 hover   

vi.翱翔，盘旋；徘徊；彷徨，犹豫

参考例句：

• You don't hover round the table.你不要围着桌子走来走去。
• A plane is hover on our house.有一架飞机在我们的房子上盘旋。

4 backwards   

adv.往回地，向原处，倒，相反，前后倒置地

参考例句：

• He turned on the light and began to pace backwards and forwards.他打开电灯并开始走来走去。
• All the girls fell over backwards to get the party ready.姑娘们迫不及待地为聚会做准备。

5 rotation   

n.旋转；循环，轮流

参考例句：

• Crop rotation helps prevent soil erosion.农作物轮作有助于防止水土流失。
• The workers in this workshop do day and night shifts in weekly rotation.这个车间的工人上白班和上夜班每周轮换一次。

6 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

7 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

8 mimic   

v.模仿，戏弄；n.模仿他人言行的人

参考例句：

• A parrot can mimic a person's voice.鹦鹉能学人的声音。
• He used to mimic speech peculiarities of another.他过去总是模仿别人讲话的特点。

9 sleek   

adj.光滑的，井然有序的；v.使光滑，梳拢

参考例句：

• Women preferred sleek,shiny hair with little decoration.女士们更喜欢略加修饰的光滑闪亮型秀发。
• The horse's coat was sleek and glossy.这匹马全身润泽有光。