题目内容
Car companies are developing vehicles that will plug into electric sockets, ust like many laptops, digital cameras, cell phones and Mp4 do. Called “plug-in vehicles”, these cars will get most of their power from electricity. Their drivers won't have to stop at gas stations as often as usual.
The technology is more than just cool. In our car-filled world, plug-in vehicles could reduce the amount of gas we use, which keeps rising in cost now and then. Besides, driving around in these vehicles may even help the environment. Gas-burning cars produce a lot of greenhouse gas, which causes global warming.
The first company-produced plug-in vehicles could hit the roads by 2020. 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-vehicle world，Li-ion(锂离子)batteries are getting the most attention. These batteries can store a large amount of energy in a small package, and they last a longer time between charges. Li-ion batteries can fit laptops, cell phones, heart instruments and other similar pocket ones.
But because cars are so big and heavy, it would still require a suitcase-sized Li-ion batteries to power about 12km of driving. What's more, the batteries are much expensive.
“A car filled with batteries could go a long distance,” says Ted Bohn, an electrical engineer in Chicago. “But it couldn't pull any people, and it would cost $100,000.” So researchers need to work 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 getting fine results.”
1.According to the passage, the main problem of the new car is ______________.
A. the developing B. the speed
C. the appearance D. the batteries
2.Which is true according to the passage?
A. The “plug-in vehicles” will use electricity completely as driving power．
B. The new technology will help protect our environment．
C. The technology of using electricity as driving is quite practical now．
D. The biggest challenge of the new technology is that it will cost us more energy．
3.How does Bohn feel about the future of the technology according to the last paragraph?
A. Confident B. Puzzled．
C. Worried． D. Disappointed．
4.According to the passage, the new technology is facing the problems except that_______．
A. the new technology cannot come into use at present
B. the cost of the new technology is quite high
C. the government won't support the technology
D. the size of the batteries is too big at present
课堂全解字词句段篇章系列答案
步步高口算题卡系列答案Everyone wants to perform well at school.Add these tips to your life and you should be on your way to being a top student!
1.I cannot stress how important it is to pay attention to what your teacher is teaching you. Take part in class discussions if you have something worth adding. Pay attention during class, especially during lectures.
Taking notes is important .You don’t need to write down every single word your teacher says but write down what he or she writes on the board，or any special fact you think you might need for a test.2.This away it will help you learn more effectively by actually thinking about what you are writing.
Don’t skip school .You will be missing out on stuff.3.However , you will have more work and you have missed lectures, Also, try not to be late for class. It' s most likely that your teacher won’t appreciate it and you will get yourself behind.
4.If you have an “I don’t care about school or this class" attitude, then teachers will be less willing to help you with problems or offer you extra credit. The same goes for lazy attitude. Have a respectful attitude to the teacher and other students. Try not to laugh when other students make mistakes.
Always ask questions.5.If you don’t understand，ask someone. Read your textbook and notes，and then if that fails ,seek help. Ask a teacher，friend，classmate, parent, etc. Get a tutor if you need one.
A．Be prepared. |
B．Write in your own words. |
C．Pay attention to everything the teacher says. |
D．Staying organized will be helpful. |
E. There is no shame in needing some help.
F. It is true that you could make up the work.
G. Keep a good attitude towards things.