Space travel is definitely bad for astronauts’ bones, reducing their bone density(密度) after only a month of weightlessness, according to French research published on Friday.

Laurence Vico and his fellow workers at St Etienne University called for more research into the effects of microgravity, after their study of 15 astronauts from the Russian MIR station showed bone loss continued throughout space flights.

“Bone loss was especially striking in four astronauts, ” the scientists reported in the Lancet Medical Journal.

They measured the bone mineral density (BMD) of bones in the forearm(前臂) and lower leg of the astronauts who had spent one to six months in space.

The BMD loss was significant in the tibia(胫骨) of the lower leg, a weight-bearing bone, but barely changed in the radius(桡骨) of the forearm. “Our results indicate the need to investigate not only different bones, but also different areas of the same bone since not all sites of the skeleton (骨架) are similarly affected by space conditions, ” they added.

Without gravity the body isn’t bearing any weight so there is no need for calcium (钙) which makes bones strong, and it becomes empty into the bloodstream.

The research team suggested in future scientists should try to determine if the loss of bone density was only on weight-bearing bones on longer flights, also the possible recovery after returning to Earth.

1. French scientists did their research on Russian astronauts, because _______.

A. they only cared for the Russian astronauts

B. they were not interested in their own astronauts

C. the Russian government invited them to do their research

D. the Russian astronauts worked in space for a long time

2. Scientists have found that _______.

A. the BMD loss may cause serious illness to astronauts

B. the BMD loss may cause some change in astronauts’ bodies

C. astronauts shouldn’t care about the BMD loss

D. astronauts should take some calcium before space travel

3. What cause the BMD loss to astronauts, according to this passage?

A. The food they eat in space.                     B. The drinks they take in space.

C. The temperature in space.                D. The gravity in space.

4. In the third paragraph, the word “striking” means ______.

A. unusual             B. simple               C. weak                 D. slow

A Brown University sleep researcher has some advice for people who run high schools: Don’t start classes so early in the morning. It may not be that the students who nod off at their desks are lazy. And it may not be that their parents have failed to enforce (确保) bedtime. Instead, it may be that biologically these sleepyhead students aren’t used to the early hour.

“Maybe these kids are being asked to rise at the wrong time for their bodies,” says Mary Carskadon, a professor looking at problem of adolescent  (青春期的) sleep at Brown’s School of Medicine.

Carskadon is trying to understand more about the effects of early school time in adolescents. And, at a more basic level. she and her team are trying to learn more about how the biological changes of adolescence affect sleep needs and patterns.

Carskadon says her work suggests that adolescents may need more sleep than they did at childhood, no less, as commonly thought.

Sleep patterns change during adolescence, as any parent of an adolescent can prove. Most adolescents prefer to stay up later at nigh and sleep later in the morning. But it’s not just a matter of choice –their bodies are going through a change of sleep patterns.

All of this makes the transfer from middle school to high school—which may start one hour earlier in the morning  ---- all the more difficult , Carskadon says. With their increased need for sleep and their biological clocks set on the “sleep late, rise late” pattern, adolescent are up against difficulties when it comes to trying to be up by 5 or 6 a.m. for a 7:30 a.m. first bell. A short sleep on a desktop may be their body’s way of saying. “I need a timeout.”

Carskadon suggests that high schools should not start classes so early in the morning because ________.

A. it is really tough for parents to enforce bedtime

B. it is biologically difficult for students to rise early

C. students work so late at night that they can’t get up early

D. students are so lazy that they don’t like to go to school early

The underlined phrase “nod off” most probably means “ _______”.

A. turn around    B. agree with others  C. fall asleep  D. refuse to work

What might be a reason for the hard transfer from middle school to high school?

A. Adolescents depend more on their parents.

B. Adolescents have to choose their sleep patterns.

C. Adolescents sleep better than they did at childhood.

D. Adolescents need more sleep than they used to.

What is the test mainly about?

A. Adolescent heath care.      B. Problems in adolescent learning.

C. Adolescent sleep difficulties.   D. Changes in adolescent sleep needs and patterns.

Wage increases to a certain level will probably help to ______ the average consumers from the effects of higher prices.

Michael Fish may soon be replaced as a weather forecaster by something truly fishier---the shark(鲨鱼).

Research by a British biology student suggests that sharks could be used to predict storms.

Lauren Smith, 24, is close to completing her study on shark’s ability to sense pressure.

If her studies prove the theory, scientists may be able to monitor the behaviour of sharks to predict bad weather.

Miss Smith had previously studied the behaviour of lemon sharks in the Bahamas.

She then used their close relatives, lesser spotted dogfish, for further research at Aberdeen University.

Her work---thought to be the first of its kind to test the pressure theory ---- resulted from the observation that juvenile blacktip sharks off Florida moved into deeper water ahead of a violent storm in 2001.

Miss Smith said: “I’ve always been crazy about traveling and diving and this led me to an interest in sharks.”

“I was delighted to have been able to research in the area for my degree. I know there’s so much more we need to understand ---- but it certainly opens the way to more research.”

It has been discovered that a shark senses pressure using hair cells in its balance system.

At the Bimini Shark Lab in the Bahamas, Miss Smith fixed hi-tech sensors to sharks to record pressure and temperature, while also tracking them using GPS (Global Positioning System) technology.

In Aberdeen, she was able to study the effects of tidal(潮汐的) and temperature changes on dogfish----none of which were harmed. She also used a special lab which can mimic(模拟) oceanic pressure changes caused by weather fronts.

She is due to complete her study and graduate later this year. She says she will be looking for a job which will give her the chance to enrich her experience of shark research.

The passage is most probably taken from _____.

A. a short-story collection        B. a popular science magazine

C. a research paper              D. a personal diary

What do we learn from the first four paragraph of the passage?

A. Sharks may be used to predict bad weather.

B. Sharks’ behaviour can be controlled.

C. Michael Fish is not qualified for his job.

D. Lauren Smith will become a weather forecaster.

Lauren Smith conducted her research by _______.

   A. removing hair cells from a shark’s balance system

   B. measuring the air pressure of weather fronts

   C. recording sharks’ body temperature

   D. monitoring sharks’ reaction to weather changes

What is the passage mainly about?

   A. A popular way of forecasting weather.

   B. A new research effort in predicting storms.

   C. Biologists’ interest in the secrets of sharks.

   D. Lauren Smith’s devotion to scientific research.

Listening to music can help me focus better. Since I discovered it two years ago，I've used music to get through boring work or to focus creatively. I've found that it can make even the dullest jobs enjoyable and help clear mental blocks to creativity.

I first noticed the good effects of music while playing video games. It was a few days before Christmas in 2005 and I was playing online video games. My parents had just given me a new MP3，so I decided to listen to music through the headphones while I played. After a few minutes I noticed a great change in my style of play. I was playing more naturally. The music relaxed me，and，to a certain extent，distracted me from the game，allowing my subconscious(潜意识的)talent to come through. The music also helped me block out the outside world. With those headphones on I was like a machine，moving from one task to the next without unnecessary thoughts or actions.  

Music can also have a great effect on mood. If I'm in a bad mood at work，I'll listen to some of Bob Marley's and get down to business. It always takes my mind off what I'm doing and makes me a happier person. The same is true for classic rock. One summer，I did a boring job collecting bottle openers by hand. Without a radio playing classic rock in the background，I would have hated life.

Listening to music with relaxing rhythms and a positive message helps you forget your work and think happy thoughts. But the results you see will depend heavily on your personal tastes. Experiment with the types of music you listen to during certain tasks. By trial and error you'll finally discover your best choice.

I'm always looking for new concentration aids，so I'd love to know what type of music works best for me.

1.We can infer that the passage was written in ________.

2.The author first discovered the effects of music ________.

3.The author mentions the experience of collecting bottle openers in Paragraph 3 to ________.