提示：
　　段首开头或段落结尾部分的句子中出现了概括句、观点句、定义句，则这些句子可能就是其所在段落的段落主题句， 如：
　　2007年综合AB概括大意完成句子考题：(60th Anniversary ceremony in Moscow
　　第3段：(段首句)The second world war is perhaps the most catastrophic(灾难性的)event that mankind has ever suffered. The war affected¹ 80 per cent of the world's people at that time, from 61 countries, and claimed 55 million lives.

　　段首句是观点句，因此很可能就是段落主题句。选项F(world’s worst disaster/世界上最严重的灾难)正好与该句内容呼应， F是答案。

　　(三)2008年教材变动情况
　　2008年教材上新增了大约17篇文章，词汇选项、阅读判断、概括大意完成句子、阅读理解、补全短文、完型填空各个题型上都有新增文章。理工类和卫生类新增的文章更体现专业性。新增文章的语言难度和问题考点设置情况在一定程度上反映了08年考题的出题趋势。

　　(难度B/A级/2008年理工类教材新增文章)

　　The Tiniest Electric Motor in the World

　　1. Scientists recently made public the tiniest electric motor ever built. You could stuff hundreds of them into the period at the end of this sentence. One day a similar engine might power a tiny mechanical doctor that would travel through your body to remove your disease.

　　2. The motor works by shuffling(来回运动) atoms(原子) between two molten metal droplets³(小滴) in a carbon nanotube(纳米管). One droplet² is even smaller than the other. When a small electric current is applied⁴ to the droplets, atoms slowly get out of the larger droplet and join the smaller one. The small droplet grows – but never gets as big as the other droplet – and eventually bumps into the large droplet. As they touch, the large droplet rapidly sops⁵ up (吸入)the atoms it had previously⁶ lost. This quick shift in energy produces a power stroke(动力行程).

　　3.The technique exploits the fact that surface tension -- the tendency of atoms or molecules⁷ to resist separating -- becomes more important at small scales. Surface tension is the same thing that allows some insects to walk on water.

　　4.Although the amount of energy produced is small -- 20 microwatts(百万分之一瓦) -- it is quite impressive(给人印象深刻的) in relation to(与...相比) the tiny scale of the motor. The whole setup is less than 200 nanometers on a side, or hundreds of times smaller than the width of a human hair. If it could be scaled up to the size of an automobile⁸ engine, it would be 100 million times more powerful than a Toyota Camry’s 225 horsepower V6 engine.

　　5. In 1988, Professor Richard Muller and colleagues made the first operating(工作的， 运行的) micromotor(微型发动机), which was 100 microns(微米) across, or about the thickness of a human hair. In 2003, Zettl's group created the first nanoscale motor. In 2006, they built a nanoconveyor(纳米传送带), which moves tiny particles along like cars in a factory.

　　6.Nanotechnology(纳米技术) engineers try to mimic⁹ nature, building things atom-by-atom. Among other things, nanomotors could be used in optical circuits to redirect light, a process called optical switching. Futurists envision(预想) a day when nanomachines(纳米机器), powered by nanomotors(纳米发动机), travel inside your body to find disease and repair damaged cells.

　　练习：

　　1.Paragraph 2_______
　　2.Paragraph 4_______
　　3.Paragraph 5_______
　　4.Paragraph 6_______
　　A.An introduction of a Toyota’s 225 horsepower V6 engine.
　　B.A description of the nanomotor in terms of power and size.
　　C.Surface tension(表面张力).
　　D.Previous inventions of nanoscale(纳米级的) products.
　　E.The working principle of the nanomotor.
　　F.Possible fields of application in the future.