NASA’s Mars detector (探测器), Opportunity, succeeded in finding signs that water once existed on the planet. Opportunity landed on Mars in January. Scientists now believe that the planet could once have supported life.
This discovery was chosen by Science, one of the world’s leading magazines, as the most important scientific achievement of 2004 last Friday.
“This little, wheeled, one-armed box went around another planet and has done something no human has ever managed,” according to Science. “It has discovered another place in the universe where life could once have existed.”
“Although we still can’t say that life could have existed in this environment, it is now certain that there was water on Mars,” said Steve Squyres, one of the scientists working on the Mars mission. The evidence comes from pictures and chemical readings taken by Opportunity. It includes marks on rocks like those caused by flowing water on Earth and salty chemicals like those found in dried-out sea-beds. Scientists said the new evidence proved beyond doubt that water has existed on Mars. But it is still unknown whether the water on Mars was like an ocean or justice.
While Opportunity has not found any signs of life, the presence of water means life is possible. “In everything we know about life on Earth, there is no example without liquid water,” Squyres said. “So water is important for the search for life on Mars.”
Researchers agree that a future mission (任务) should bring back physical samples (样品). But some scientists worry about the risk that this could introduce dangerous foreign creatures to Earth. “The problem here is how to get the samples back,” Squyres replied. “I think it is our responsibility to limit any risk.”
【小题1】________ prove that water existed on Mars.

Every few years, two groups carry out a study of how many Americans wash their hands after using the toilet. These groups are the American Society for Microbiology and the American Cleaning Institute, formerly the Soap and Detergent Association.
There was good news in the latest study. Researchers found that eighty-five percent of adults washed their hands in public restrooms last month. That was the most since the studies began in 1996.
Researchers visited restrooms at a baseball park in Atlanta and a science museum and aquarium(水族馆) in Chicago. They also visited two train stations in New York City and a large farmers’ market in San Francisco. In all, they observed about six thousand adults, with females and males equal in number.
The researchers found that seventy-seven percent of men and ninety-three percent of women washed their hands. That was up from sixty-six percent of men and eighty-eight percent of women in the last study three years ago.
The lowest rate of hand washing among men was at Turner Field, home of the Atlanta Braves baseball team. Only sixty-five percent of men washed their hands, compared to all but two percent of women.
Chicago and San Francisco had the most hand washers—eighty-nine percent of adults. Atlanta followed at eighty-two percent. New York had the lowest rate, at seventy-nine percent of the adults observed at Grand Central Station and Penn Station.
The findings of the observational study conflicted(不一致) with the findings of a separate telephone survey of about one thousand people. Ninety-six percent of them said they always washed their hands after using public restrooms.
Almost nine out of ten also said they always washed after using the bathroom at home.
Hand washing can help prevent the spread of many different infections.
To clean your hands well, wet them first and rub in soap for at least twenty seconds, including between the fingers and under the nails. Then wash under running water. In a public restroom, if you dry your hands with a paper towel, you should also use the towel to shut off the water and open the door.
Hand washing is also important when preparing food and after changing a baby’s diaper(尿布). You should also wash if you cough or sneeze into your hands.
【小题1】According to the latest study, about ____ women washed their hands after using public bathroom.

Every few years, two groups carry out a study of how many Americans wash their hands after using the toilet. These groups are the American Society for Microbiology and the American Cleaning Institute, formerly the Soap and Detergent Association.

There was good news in the latest study. Researchers found that eighty-five percent of adults washed their hands in public restrooms last month. That was the most since the studies began in 1996.

Researchers visited restrooms at a baseball park in Atlanta and a science museum and aquarium(水族馆) in Chicago. They also visited two train stations in New York City and a large farmers’ market in San Francisco. In all, they observed about six thousand adults, with females and males equal in number.

The researchers found that seventy-seven percent of men and ninety-three percent of women washed their hands. That was up from sixty-six percent of men and eighty-eight percent of women in the last study three years ago.

The lowest rate of hand washing among men was at Turner Field, home of the Atlanta Braves baseball team. Only sixty-five percent of men washed their hands, compared to all but two percent of women.

Chicago and San Francisco had the most hand washers—eighty-nine percent of adults. Atlanta followed at eighty-two percent. New York had the lowest rate, at seventy-nine percent of the adults observed at Grand Central Station and Penn Station.

The findings of the observational study conflicted(不一致) with the findings of a separate telephone survey of about one thousand people. Ninety-six percent of them said they always washed their hands after using public restrooms.

Almost nine out of ten also said they always washed after using the bathroom at home.

Hand washing can help prevent the spread of many different infections.

To clean your hands well, wet them first and rub in soap for at least twenty seconds, including between the fingers and under the nails. Then wash under running water. In a public restroom, if you dry your hands with a paper towel, you should also use the towel to shut off the water and open the door.

Hand washing is also important when preparing food and after changing a baby’s diaper(尿布). You should also wash if you cough or sneeze into your hands.

1.According to the latest study, about ____ women washed their hands after using public bathroom.

A．1,980            B．2,310             C．2,640            D．2,790

2.Which of the following shows the right order of washing hands correctly?

a. Wash your hands under running water.

b. Rub your hands in soap for not less than twenty seconds.

c. Wet your hands.

d. Dry your hands with a paper towel.

e. Open the door, using a paper towel.

f. Shut off the water with a paper towel.

A．cbdaef           B．cdabfe            C．cbadfe            D．cdabef

3.Which of the following can be the best title for the passage?

A．Hand washing is up in public restrooms in the US

B．Americans like washing their hands so much

C．Adults have their hands washed in public restrooms

D．Why hand washing never enjoys popularity in the US

You’re rushing to work and a man ahead of you collapses on the sidewalk. Do you stop to help? In a study of by-standers, it was found that some people avert their gaze and keep on  walking rather than stop and get involved.
“There is a tendency to decide that no action is needed.” says a psychologist. “The first thoughts that pop into your mind often keep you from offering help. In order to take action, you have to work against them.” Here are some common thoughts that might prevent you from helping.
● Why should I be the one? I’m probably not the most competent（有能力的） person in this crowd. You might think someone older or with more medical knowledge should offer assistance.
● What if he doesn’t really need my help? The fear of embarrassment is powerful; no one wants to risk looking foolish in front of others.
● No one else looks concerned- this must not be a problem. We can follow the people around us, but most people tend to hold back their emotions in public.
“If you spot trouble and find yourself explaining inaction, force yourself to stop and evaluate the situation instead of walking on,” says the psychologist. “Then retry to involve other people; you don’t have to take on the entire responsibility of being helpful. Sometimes it’s just a matter of turning to the person next to you and saying, ‘It looks like we should do something.’ Or asking someone if an ambulance has been called and, if not, to call for one. Once you take action, most people will follow you.”
【小题1】Which is NOT the common thought that stops you from helping others?

Recently we told you about a finding that more years of school could help students get higherscores on intelligence tests．That was the finding of a study of teenage males in Norway．Now，other research shows that physical activity may help students do better in their classes .

The research comes as educators in some countries are reducing time for activities like physical education．They are using the time instead for academic subjects like maths and reading．The studies appeared between 2007 and 2013．They included more than 55，000 children，aged 6 to 18．

Amika Singh：“Based on the results of our study，we can conclude that being physically active is beneficial for academic performance. There are，first，Physiological explanations，like more blood flow, and so more oxygen to the brain．Being physically active means there are more hormones(荷尔蒙)produced like endorphins(内啡肽)．And endorphins make your stress level lower and? your mood improved, which means you also perform better.”

Also，students involved in organized sports learn rules and how to follow them．This could improve their classroom behavior and help them keep their mind on their work．

The study leaves some questions unanswered，however．Ms．Stash says it is not possible to say whether the amount or kind of activity affected the level of academic improvement．This is because of differences among the studies .

Also．they were mostly observational studies．An observational study is where researchers do not do controlled comparisons．They only describe what they observe．So they might observe a link that students who are more active often have better grades．But that does not necessarily mean being active was the cause of those higher grades．

The researchers said they found only two high - quality studies．They called for more high-

quality studies to confirm their findings．They also pointed out that “outcomes for other parts of the world may be quite different. ”

Still，the general finding was that physically active kids are more likely to do better in school．Ms．Singh says schools should consider that finding before they cut physical education programs．Her paper on “Physical Activity and Performance at School”is published in the Archives of Pediatric and Adolescent Medicine．

1.The passage mainly tells us that ＿＿＿＿

A．a research on physical education has been done by the researchers

B．there exists a possibility that physical activity leads to higher grades

C．the amount or kind of activity directly affects academic level

D．the research shows that the children aged 6 to 1 8 don't do sports

2.Which of the following is TRUE?

A．Being mentally active is good for academic subjects．

B．The more hormones you have，the more stressed you will get．

C．They have found many high-quality studies to prove the research．

D．The educators in the research think studies，not exercise，mean much to students．

3.The underlined sentence in Paragraph 7 probably means ＿＿＿＿.

A．good marks result from high-quality study

B．findings probably vary in different areas

C．physical activity will spread all over the world

D．academic performance depends on the surroundings

4.What's the purpose of writing the passage?

A．To call our attention to the sports at school．

B．To introduce all types of physical activities．

C．To represent the academic performance．

D．To improve students' health ．