From the passage, we can learn . A. we can buy one of “plug-in hybrids now B.——青夏教育精英家教网—

练习册

练习册
试题

From the passage, we can learn . A. we can buy one of “plug-in hybrids now B. all people will buy one after 20l0 C. this kind of car can carry two persons D. some problems about “plug-in hybrids remain to be done 答案 59.C 60.D 61.D Passage 13 (江西省抚州一中2009届高三第四次模拟考试B篇) How many things can you see in the night sky? A lot! On a clearnight you might see the Moon, some planets, and thousands of sparkling stars. You can see even more with a telescope. And with bigger and bigger telescopes you can see more and more objects in the sky. And you can see those objects in more and more detail. But scientists believe there are some things in the sky that we will never see. We won't see them with the biggest telescope in the world, on the clearest night of the year. That's because they're invisible. They're the mysterious dead stars called black holes. You might find it hard to imagine that stars die. After all, our Sun is a star. Year after year we see it up in the sky, burning brightly, giving us heat and light. The Sun certainly doesn't seem to be getting old or weak. But stars do burn out and die after billions of years. As a star's gases burn, they give off light and heat. But when the gas runs out, the star stops burning and begins to die. As the star cools, the outer layers of the star pull in toward the center. The star squashes into a smaller and smaller ball. If the star was very small, the star ends up as a cold, dark ball called a black dwarf. If the star was very big, it keeps squashing inward until it's packed together tighter than anything in the universe. Imagine if the Earth were crushed until it was the size of a tiny marble. That's how tightly this dead star, a black hole, is packed. What pulls the star in toward its center with such power? It's the same force that pulls you down when you jump--the force called gravity. A black hole is so tightly packed that its gravity sucks in everything--even light. The light from a black hole can never come back to your eyes. That's why you see nothing but blackness. So next time you stare up at the night sky, remember: there's more in the Sky than we can see! Scattered in the silent darkness are black holes--the great mystery of space. 【查看更多】

题目列表(包括答案和解析)

When a handheld video game runs out of power, all you have to do is plug it in and charge it up. Within a few years, some of you might do the same thing with mom’s car.

Automobile companies are developing vehicles that will plug into electric sockets （插座）, just like many laptops, digital cameras, cell phones and small video game players do. Called “plug-in hybrids （混合动力汽车）,” these cars will get most of their power from electricity. Their drivers will rarely have to stop at gas stations.

The technology is more than just cool. In our automobile-filled world, plug-in vehicles could reduce the amount of gasoline we use. That gas is made from crude oil, which has been kept rising in cost. Plus, driving around in these hybrids may even help the environment. Gas-burning cars produce a lot of carbon dioxide, a type of greenhouse gas. These gases stay in the atmosphere, where they trap heat and cause global warming.

The first company-produced plug-in hybrids could hit the roads by 20l0. But engineers still have a lot of work to do to make the technology practical and inexpensive.

Batteries are the biggest challenge. In the plug-in-hybrid world, Li-ion batteries are getting the most attention. These batteries can store a large amount of energy in a small package, and they last a relatively long time between charges. Li-ion batteries are standard in laptops, cell phones, heart devices and similar portable devices.

But because cars are so big and heavy, it would still require a suitcase-sized Li-ion battery to power about l2km of driving. What’s more, the batteries are extremely expensive.

“A car filled with batteries could go a long distance,” says Ted Bohn, an electrical engineer in Chicago. “But it couldn’t haul （拖拉） any people, and it would cost $l00,000.”

So researchers need to figure out how to make batteries smaller and cheaper, among other questions.

“The answers don’t exist yet,” Bohn says. “As a kid I thought someone someplace knows the answer to everything. All of these questions haven’t been decided. That’s what engineering is about ― making a guess, running tests and fine-tuning results.”

59. The writer wrote this passage with the purpose of __________________.

A. how to charge the handheld video game up

B. explaining a newly-developed battery

C. introducing a new car

D. telling us how to make the new battery cheaper

60. Which is true according to the passage?

A. Plug-in hybrids will do no harm to the environment.

B. Li-lion batteries in laptops can be used on plug-in hybrids.

C. Some companies can produce plug-in hybrids now.

D. Drivers of plug-in hybrids will spend less money on gasoline.

61. From the passage, we can learn _________________.

A. we can buy one of “plug-in hybrids” now

B. all people will buy one after 20l0

C. this kind of car can carry two persons

D. some problems about “plug-in hybrids” remain to be done

查看答案和解析>>

(江苏省启东中学2009届高三最后一卷B篇)