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"Our invention，"Kennedy says，"came from seeing how we could transform technology we saw every day in the United States and move it into new markets for people who didn't have a lot of money．"
At the core of Portable Light technology are devices called high-brightness light-emitting diodes （高亮度发光二极管），or HB LEDs. These tiny lights appear in digital clocks，televisions，and streetlights．
LEDs are completely different from the light bulbs （灯泡）．Most of those glass bulbs belong to a type called incandescent lights （白炽灯）．Inside，electricity heats a metal coil （线圈）to about 2，200 degrees Celsius．At that temperature，bulbs give off light we can see．
Ninety percent of energy produced by incandescent lights，however，is heat-and invisible. With all that wasted energy，bulbs bum out quickly．They are also easily broken．
LEDs，on the other hand，are like tiny pieces of rock made up of molecules （分子）that are arranged in a crystal structure．When an electric current passes through an LED，the crystal structure produces light．Unlike incandescent bulbs，they can produce light of various colors．Within an LED，the type of molecules and their particular arrangement determines what color is produced．
31. The Huichol don't use electricity because
A. it is too difficult for them to change their lifestyle
B. they know nothing about it
C. it costs too much to string power lines
D. they don't need it
32．To make a living，the Huichol create artwork and
A．sell it in cities far away from their villages．
B．sell it to tourists in their villages.
C．display it in their village museum．
D．keep it in their homes to attract tourists．
33．The central part of the Portable Lights technology is
A．Glass Bulbs．
B．HB LEDs.
C．digital clocks.
D．incandescent lights．
34. All of the following are disadvantage of incandescent lights EXPECT
A. they burn out quickly
B. they are easily broken
C. they are not bright enough.
D. they waste most of the energy produced
35．LEDs are different from light bulbs in that
A．LEDs can send out light of different colors.
B．LEDs are made up of tiny pieces of rock.
C．LEDs belong to incandescent lights.
D．LEDs look like crystals.
第二篇 The book of life
So far, scientists have named about 1.8 million living species（物种）, and that's a just a small part of what probably exists on Earth. With so many plants, animals, and other creatures coveting the planet, it can be tough to figure out what type of spider is moving up your leg or what kind of bird is flying by.
A soon-to-be-started Web site might help. An international team of researchers has announced the creation of Web-based Encyclopedia（百科全书）of life(EOL). The project aims to catalog every species on Earth in a single, easy-to-use reference guide.
To get the encyclopedia started, the creators will use information from scientific databases（数据库）that already exist. And eventually, in special sections of the site, nonscientist with specialized（专门的）knowledge will get to join in. Bird-watchers, for example, will be able to input which birds they've seen and where. The technology for this kind of tool has only become available.
As the EOL develops, you might find it useful for school projects. The site will feature special pages for kids who are studying ecosystems (生态系统) in their neighborhoods. To make sure the encyclopedia is accurate, scientists will review much of the information added to it. People who visit the site will be able to choose to leave out pages that haven't been reviewed.
Another convenient feature of the EOL is that you'll be able to pick the level of detail you want to see to match your interest, age, and knowledge. If you wanted to learn about bears for a science class report, for example, you could use the "novice" setting to get basic information about the animals. On the "expert" setting, on the other hand, you could get much more detailed information about the history, literature, and exploration of bears.
It now takes years for scientists to collect all the data they need to describe and analyze species. The creators of the Encyclopedia of Life hope that their new tool will speed up that process.
36. "Spider" and "bird" mentioned in Paragraph 1 are examples to illustrate
A. there are numerous living species on Earth.
B. animals are people's friends.
C. it is easy to see spiders and birds.
D. there are many types of spiders and birds.
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