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【单选题】
The Wonderful World of Small There's a quiet revolution going on, and its name is nanotechnology. A host of innovations are coming our way. Some seem almost magical, like the new material created in 2004 by Ray Baughman, a professor at the University of Texas. It's stronger than steel, transparent, very, very light. A hectare-size sheet would weigh just 280 grams. When the professor announced that he hadn't decided what to call it, he started to get emails from around the world suggesting names. Since it was so light and strong, people started calling it 'mithril'--the name of a highly prized type of armor used in The Lord of Rings. There are other discoveries too--perhaps not so astounding, but practical and pleasant. Now there are socks that don't get smelly, pants that resist stains, windows that repel dirt and toilets that clean themselves. All this results from exploring the world of the very, very small. Nano comes from the Greek word from dwarf. Usually nanotechnology is defined as the study and manipulation of matter smaller than 100 nanometers(毫微米)--that's the scale of things like molecules and viruses. Ten hydrogen atoms pressed together against each other are just one nanometer long. And one million nanometers fit into a millimeter. Hard to grasp? Think of it this way: If everyone in Manila were a nanometer wide, the entire population, standing shoulder to shoulder, would fit on your thumbnail. Stunning Uses of Nanotechnology Like Alice in Wonderland, researchers in Nanoland find themselves in a world where old rules don't apply. Small things behave differently. This is behind several innovations, including the self-cleaning toilet. The toilet bowl is sealed with a super-smooth glaze (涂层) that has microscopic holes under 30 nanometers. Because they're smaller than bacteria or other tiny particles, there's not enough room for dirt to get stuck in the surface. Flushing is basically all the work you have to do. Researchers in Nanoland are also making really, really small things with astonishing properties--like the carbon nanotube. Chris Papadopoulos of the University of Victoria, says, 'The carbon nanotube is the poster boy for nanotechnology.' In your pencil, carbon, in the form. of graphite (石墨), is soft and easily broken. But a carbon nanotube is tough as nails--much tougher in fact. It's very thin sheet graphite that's formed into a tube. These tiny straw-like cylinders, which can be as small as half a nanometer wide, are up to 100 times stronger than steel and six times lighter. They are the hardest, stiffest, strongest materials known and are among the world's best conductors of heat and electricity. They can carry some 1000 times more electricity current than copper wire. Everybody wants them, but until now they've been in short supply and pricey. The current annual production, worldwide, is only 300 kilograms. At $ 860 a gram, carbon nanotubes cost 50 times more than gold. When it comes to finding uses for carbon nanotubes, the range is huge. The National Research Council Canada (NRC) is looking at harnessing their strength by embedding them in construction materials, among other applications. The Boeing Company thinks nanotubes may be the source of futute improvements for high-performance aircraft. Some of the most stunning uses come out of Ray Baughman's research. Employing what he calls the 'ancient technology of spinning,' Baughman and his team developed a way of spinning carbon nanotubes into fibers that are four times tougher than spider silk, the toughest natural filament (细丝). Since they also conduct electricity, the futuristic yarns could be woven into 'smart' clothing that stores electricity, is potentially bulletproof and incorporates sensors capable of adjusting the temperature of garment. The fibers could also be made into cables for suspension bridges much longer than any we
A.
Y
B.
N
C.
NG
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举一反三
【单选题】下列各项中会使企业财务报表反映的偿债能力大于实际偿债能力的是( )
A.
企业的长期偿债能力一向很好
B.
未做记录的为别的企业提供的信用担保
C.
未使用的银行存款限额
D.
存在将很快处理的存货
【单选题】下列各项中会使企业财务报表反映的偿债能力大于实际偿债能力的是( )
A.
企业长期偿债能力一向很好
B.
未记录的为别的企业提供的信用担保
C.
 未使用的银行贷款限额
D.
 存在很快处理的存货
【单选题】滤镜不能应用于什么中?
A.
文本
B.
影片剪辑
C.
按钮
D.
图形对象
【单选题】下列各项中,会使财务报表反映的偿债能力大于实际偿债能力的是( )
A.
企业的长期偿债能力一向很好
B.
未做记录的为别的企业提供的信用担保
C.
存在很快处理的存货
D.
未使用的银行贷款限额
【单选题】下列各项中会使企业财务报表反映的偿债能力大于实际偿债能力的是
A.
企业的长期偿债能力一向很好
B.
未做记录的为别的企业提供的信用担保
C.
未使用的银行贷款限额
D.
存在很快处理的存货
【单选题】滤镜不能应用于 ()
A.
文本
B.
影片剪辑
C.
按钮
D.
图形对象
【判断题】The author's husband was not good at playing table tennis, and that was why he was criticized by his father.
A.
正确
B.
错误
【简答题】20 413 13 021
【简答题】用简便方法计算. 11- 5 12 - 7 12 ( 3 4 + 1 3 )×12 2 9 × 4 13 + 4 13 ÷ 9 7 .
【单选题】下列各项中会使企业财务报表反映的偿债能力大于实际偿债能力的是( )。
A.
企业的长期偿债能力一向很好
B.
未做记录的为别的企业提供的信用担保
C.
未使用的银行贷款限额
D.
存在将很快处理的存货
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