As the word becomes increasingly populated , It is also Becoming alarmingly polluted . Fortunately , there are many ways that you can help deal with the negative effects that we impose(施加)on the environment . One of these is driving an electric car.

Electric cars produce about 80 pe rcent less pollution than cars with gas-powered motors. In fact, the only reason that electric cars produce any pollution at all is that their electric energy is produced by power plants-electric cars themselves produce no waste. When energy comes from large sources such as power plants, it’s easier to control, so there’s less waste than if the energy is produced by many smaller sources, such as the gas engines in individual cars.

Furthermore, electric cars are simply more efficient than gas-powered cars for several reasons. First, electric cars have regenerative braking, which means that when you use the brakes in an electric car , the battery has a chance to recharge (再充电).On the contrary , when you brake in a gas-powered car ,you actually use energy . Also, during the production of electric cars, more time and energy is spent making the design lighter and more aerodynamic so that there will be less drag(阻力) from the wind. This allows then to travel farther using less energy than a gas-powered car would use to go the same distance.

In addition to the environmental benefits of driving electric cars , there are also financial and time-saving benefits for the drivers . For one , they cost less to maintain (维修). The cost of charging an electric car is about 20 percent of the cost of gas, and electric cars require far less maintenance than gas-powered cars . This is due , in part , to the fact that electric cars have no cooling system , fan belts , radiators , hoses , or oil-just a battery . There are fewer moving parts overall , so there are fewer possible problems . Also , after the body of an electric car gives out , the engine can be reused in another body . Electric cars can also save people time . While gas-powered cars require visits to a mechanic every few months , the only routine maintenance required by electric cars is replacing the battery every four years.

Overall , there are numerous benefits of driving an electric car . Tt may take a little getting used to , but in the long run , the use of electric cars can help preserve the environment and give people more time and money to be put to better use.

1.What can we learn from the second paragraph?

A. Less than 80 percent pollution is produced by cars.

B. Gas-powered cars get energy from power stations.

C. Electric cars themselves don’t produce any waste.

D. It’s difficult to control energy from power plants.

2.According to the passage , which of the following is TRUE?

A. The battery can be reused after the body of an electric car gives out.

B. Replacing the engine every four years is required for an electric car .

C. It may take no time to see the popularity of driving electric cars.

D. Electric cars cost less to maintain because of fewer moving parts.

3.What is the writer’s purpose of writing this passage?

A. To compare two kinds of cars.

B. To show a new way of driving.

C. To suggest driving electric cars.

D. To introduce a useful invention?

4.Which is the best title of the passage?

A. The Best Way to Protect the Environment

B. Electric Cars are Worthy of a Second Look

C. The Greatest Invention in the New Century

D. Driving Electric Cars Saves Times and Money

On June 26, 2000, two scientists, called Francis Collins and Craig Venter, told the world that they could now read the whole “map” of the human body: DNA. DNA is something that everybody has, and it tells the body what to do. DNA is the reason that we look like our mother and father, because we get some of their DNA to make our own.

People have been trying to understand the human body for a long time. In 1860, Gregor Mendel discovered a special reason why we look the same as other people in our family. It is because of small things named “genes” in our body. In 1953, James Watson and Francis Crick made another discovery and found out that those small parts are real messages written in the DNA with a special language.

In 1961, Marshall Nirenberg and Johann Matthaei found a message in DNA showing how DNA tells the cell (细胞) to build its parts. Scientists have now found all the words in the DNA map, but we still do not understand what they all do. By understanding what just one “word” means, we can help save more people from several illnesses.

Most people hope that this will help make better medicine and help sick people. Other people worry that when people begin to know more words and find out lots of other information, we might use it in a wrong way, just to make people more attractive, or stop sick people from getting jobs. Man would have to meet a lot of trouble if DNA technic wasn’t limited in use.

1.When did we first know why we look like other people in our family?

A. In 1860. B. In 1953.

C. In 1961. D. In 2000.

2. What does the underlined word “gene” mean?

A. The “map” of DNA. B. A special language.

C. Small parts of DNA. D. DNA.

3.What did the two scientists first discover in 1961?

A. The “map” of DNA. B. A new illness.

C. The language of DNA. D. A message of DNA.

4. What can we do if we understand some “words” of the language inside the body?

A. Make people get new jobs.

B. Make medicine for illnesses.

C. Make maps of human.

D. Make people less attractive.

5.What do people think about this work?

A. It can cause good or bad results.

B. It can cause only good results.

C. It can cause good results but won’t work.

D. It can cause only bad results.

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