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职称英语理工类考试考前每日一练 概括大意与完成句子 The Tiniest Electric MOtOr in the W0rId 1. Scientists recently made puhlic the tinjest electric motor ever huilt. You ld stuff hundrefls 0f them into the period at the end 0f this sentence. One day a similar engine might power a tiny mechanical doetor that WOUld travel through your hodv t0 remove your disease. 2. The motor workshy shuffling atoms between two molten metal droplets in a carhon nanotube. One droplet is even smallerthan the 0ther. When a small electric current is applied to the droplets， atoms s10wly get out of the larger droplet and join the smaller one.The sinall droplet growshut never gets as big as the other dropletand eventually humps i。nto the large droplet. As they touch，the large dmplet rapidly sops up the atoms it had prevviouslv lost. This quick shift in energy produces a power stroke. 3. The technique exploits the flact that surface tensionthe tendeney 0f atoms or molecules to re一 sist separatlngbecomes more important at small scales. Surfaee tension is the same thing that aUOWS some insects t0 walk on water. 4. Although the amount 0f energy produced is small--20 microwattsit is quite inlpressive in relation t0 the tiny seale of the motor. The whole setup is less than 200 nanometers 0n a side. 0r hundreds of times smaIler than the width 0f a human hair. If it COUld he sealed uD to the size 0f an au tomobile engine，it wonld be 1 00 milJion times more powerful than a Toyota Camrys 225 horsepower V6 engine. | 
