共用题干

共用题干
第三篇

Weaving with Light

In the Sierra Madre mountain range of west central Mexico,the native Huichol people live much the
way their ancestors did一without electricity,That’s because it's too expensive to string power lines to the
remote mountain areas where they live.To help support themselves,the Huichol create beautiful artwork.
They sell their art in cities hundreds of miles away from their villages.And without electricity一at home or
on the road,they can only work during daylight hours?When it gets dark,they must stop whatever they're
doing.
Now，a team of scientists,designers,and architects is using new technologies to provide the Huichol
with light after the sun sets.The scientists'technique involves weaving tiny electronic crystals into fabrics
that can be made into clothes,bags,or other items.
By collecting the sun’s energy during the day,these lightweight fabrics provide bright white light at
night一 Their inventors have named the fabrics" Portable（轻便的）Lights."Portable Lights have the potential
to transform the lives of people without electricity around the world.
At the core of Portable Lights 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 mnean-
descent lights,however,is heat一and invisible.With all that wasted energy,bulbs burn 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 a LED,the crystal structure produces light. Un-
like incandescent bulbs,they can produce light of various colors.Within a LED,the type of molecules and
their particular arrangement determine what color is produced.

LEDs are different from light bulbs in that__________.
A:LEDg are made up of tiny pieces of rock
B:LEDs can send out light of different colors
C:LEDs belong to incandescent lights
D:LEDs look like crystals