更多"第二篇 Superconductor"的相关试题:
[单项选择]第二篇 Superconductor Ceramic(陶瓷)
An underground revolution begins this winter.with the flip(轻击)of a switch,30,000 homes in one part of Detroit will soon become the first in the country to receive electricity transmitted by ice.cold high.performance cables.Other American cities are expected to follow Detroit’s example in the years ahead.which could conserve enormous amounts of power.
The new electrical cables at the Frisbie power station in Detroit are revolutionary because they are made of superconductors.A superconductor is a material that transmits electricity with little or no resistance.Resistance is the degree to which a substance resists electric current.All common electrical conductors have a certain amount of electrical resistance.They convert at least some of the electrical energy passing through them into waste heat.Superconductors don’t No one understands how superconductivity works.It just does.
Making superconductors isn’t easy.A superconducto
A. With a flip of swish.electricity can be transmitted.
B. Other American cities can benefit from the high performance cables.
C. Great amounts of power can be conserved.
D. Detroit will first receive electricity transmitted by the new electrical cables
[单项选择]第二篇
Shopping at Second-hand Clothing Stores
When 33-year-old Pete Barth was in college, shopping at second-hand clothing stores was just something he did - "like changing the tires on his car." He looked at his budget, and decided he could save a lot of money by shopping for clothes at thrift shops.
"Even new clothes are fairly disposable (用后即丢掉的) and wear out after a couple of years," Barth said. "In thrift shops, you can find some great stuff whose quality is better than new clothes."
Since then, Barth, who works at a Goodwill thrift shop in the US state of Florida, has found that there are all kinds of reasons for shopping for second-hand clothing. Some people like him, shop to save money. Some shop for a crazy-looking shirt. And some hop as a means of conserving energy and helping the environment.
Pat Akins, an accountant at a Florida Salvation Army (SA) (救世军) thrift shop, said hat, for her, shopping at thrift shops is a way to h
A. He is 33 years old now.
B. He works at a Goodwill thrift shop.
C. He works at a Salvation Army thrift shop.
D. He was a college student many years ago.
[单项选择]第二篇
Mind-reading Machine
A team of researchers in California has developed a way to predict what kinds of objects people are looking at by scanning (扫描) what’s happening in their brains.
When you look at something, your eyes send a signal about that object to your brain. Different regions of the brain process the information your eyes send. Cells in your brain called neurons (神经元) are responsible for this processing.
The fMRI (functional Magnetic Resonance Imaging) (功能性磁振造影) brain scans could generally match electrical activity in the brain to the basic shape of a picture that someone was looking at.
Like cells anywhere else in your body, active neurons use oxygen. Blood brings oxygen to the neurons, and the more active a neuron is, the more oxygen it will consume. The more active a region of the brain, the more active its neurons, and in turn, the more blood will travel to that region. And by using fMRI, scientist
A. The magnetic system in the brain.
B. The central part of the heart.
C. Oxygen-rich blood.
D. Neurons in the brain.
[单项选择]第二篇 Crystal Ear
One day a friend asked my.wife Jill if I wanted a hearing aid.“He certainly does.”repliedJill.After hearing about a remarkable new product.Jill finally got up the nerve to ask me if I’dever thought about getting a hearing aid.“No way,”I said.“It would make me look 20 years older.” “No。no。”she replied.”This is entirely different.It’s Crystal Ear!”
Jill was right.Crystal Ear is different—not the old. Styled body worn over-the.ear aid。but
all advanced personal sound system so small that it’s like contacts(隐形眼镜)for your ears.And Crystal Ear is super-sensitive and powerful.too.You will hear sounds your ears have been missing for years.Crystal Ear will make speech 10uder,and the sound is pure add natural.
I couldn’t believe how tiny it is.It is smaller than the tip of my little finger and it’s almost invisible When worn.There are no wires。no behind—the.ear device.Put it in your ear and its ready—to-wear mold(形状)fits comfortably.Si
A. it would make him look old.
B. it would make him nervous.
C. it was too expensive.
D. it was old-styled.
[单项选择] 第二篇 Medical Education
In 18th.century colonial America,those who wanted to become physicians either learned as personal students from established professionals or went abroad to study in the traditional schools of London,Paris{and Edinburgh.Medicine was first taught formally by specialists at the University of Pennsylvania,beginning in 1765,and in 1767 at King’s College(now Columbia University),the first institution in the colonies to give the degree of doctor of medicine.Following the American Revolution,the Columbia medical faculty(formerly of King’S College) was combined with the College of Physicians and Surgeons,chartered in 1809,which survives as a division of Columbia University.
In 1893 the Johns Hopkins Medical School required all applicants to have a college degree and was the first to afford its students the opportunity to further their training in an attached teaching hospital.The growth of medical schools attached with established institu
A. how medicine is taught in America.
B. how medical education has developed in America
C. how the American educational system works.
D. how one can become a good doctor.