A recent study, published in last week’s Journal of the American Medical Association, offers a picture of how risky it is to get a lift from a teenage driver. Indeed, a 16-year-old driver with three or more passengers is three times as likely to have a fatal accident as a teenager driving alone. By contrast, the risk of death for drivers between 30 and 59 decreases with each additional passenger.

The author also found that the death rates for teenage drivers increased dramatically after 10 p.m., and especially after midnight, with passengers in the car, the driver was even more likely to die in a late-night accident.

Robert Foss, a scientist at the University of North Carolina Highway Safety Research Center, says the higher death rates for teenage drivers have less to do with “really stupid behavior” than with just a lack of driving experience. “The basic issue.” he says, “is that adults who are responsible for issuing licenses fail to recognize how complex and skilled a task driving is.”

Both he and the author of the study believe that the way to mitigate (使……缓解)the problem is to have states institute so-called graduated licensing systems, in which getting a license is a multistage process. A graduated license requires that a teenager first prove himself capable of driving in the presence of an adult, followed by a period of driving with night of passenger restrictions, before graduating to full driving privileges.

Graduated licensing systems have reduced teenage driver crashes, according to recent studies, About half of the states now have some sort of graduated licensing system in place, but only 10 of those states have restrictions on passengers, California is the strictest, with a novice(新手)driver prohibited from carrying any passenger under 20(without the presence of an adult over 25)for the first six months.

Which of the following situations is most dangerous according to the passage?

A． Adults giving a lift to teenagers on the highway after 10 p.m.

B． A teenager driving after midnight with passengers in the car.

C． Adults driving with three or more teenage passengers late at night.

D． A teenager getting a lift from a stranger on the highway at midnight.

According to Robert Foss, the high death rate of teenage drivers is mainly due to ________

A． their frequent driving at night

B． their improper way of driving?

C． their lack of driving experience

D． their driving with passengers

According to Paragraph 3. which of the following statements is TRUE?

A． Teenagers should spend more time learning to drive.

B． Driving is a skill too complicated for teenagers to learn.

C． Restrictions should be imposed on teenagers applying to take driving lessons.

D．The licensing authorities are partly responsible for teenagers' driving accidents.

A suggested measure to be taken to reduce teenagers' driving accidents is that ________ .

A． driving in the presence of an adult should be made a rule

B． they should be prohibited from taking on passengers

C． they should not be allowed to drive after 10 p.m.

D． the licensing system should be improved

A new study has found no evidence that sunscreen, commonly used to reduce the risk of skin cancer, actually increases the risk.

Researchers from the University of Iowa based their findings on a review of 18 earlier studies that looked at the association between sunscreen use and melanoma (黑素瘤)．They said that they found faults in studies that had reported associations between sunscreen use and higher risk of melanoma.

Most health experts believe that by protecting the skin from the harmful effects of the sun, sunscreen helps prevent skin cancer, which is increasing in incidence (发生率) faster than any other cancer in the United States.

But questions has been raised about sunscreen and whether it may has opposite effect, perhaps by allowing people to remain exposed to the sun longer without burning.

The researchers said that among the problems with some earlier studies is that they often failed to take into account that those people most at risk for skin cancer--- people with fair skin and freckles (雀斑), for example--- are more likely to use sunscreen．As a result, it may appear that sunscreen users get cancer more often.

The studies, which generally relied on volunteers to recall their sunscreen use, were also unable to prove how well the products had been applied, said the new study.

People with fair skin and freckles          .

       A．seldom use sunscreen             

       B．are more in danger of skin cancer

       C．can be free from the harm of the sun  

       D．often expose themselves to the sun

We can learn from the passage that          .

       A．sunscreen users get skin cancer more often

       B．the volunteers have proved the effect of sunscreen

       C．the new study was based on the experiences of volunteers

       D．the number of skin cancer patients is increasing in America

Which of the following can be the best title for this passage?

       A．Sunscreen to Prevent Skin Cancer   

       B．Sunscreen to Increase Skin Cancer

       C．Skin Cancer Caused by Sunscreen   

       D．Skin Cancer Caused by Freckles

A Concussion（脑震荡） happens when the brain is shaken, often in a car crash or a fall or a strike on; the head in sports．Concussions can be mild, but doctors may order a CT scan to look for a more serious injury．But a recent study warned that more children than necessary are being exposed（使遭受） to radiation this way．

A national team led by two doctors at the University of California, Davis, studied hospital records from thousands of children with head injuries. They found that in many cases, the risk of developing cancer from the radiation outweighed the risk of a serious brain injury.

The study found that one in five children over age two had a low risk of serious injury but received CT scans anyway. The same was true of almost one in four children under two years of age.

The researchers have developed rules to predict if a head injury is serious enough for a scan. For children under two, doctors are advised against it if there is:

·Normal mental activity.

·No swelling in the back of the head.

·No feeling of a broken bone in the skull. (头骨)

·And no loss of consciousness for more than five seconds.

Doctors should also consider how the child was injured and whether the parents say the child is acting normally.

For patients from two to eighteen, the guidelines are similar —— except there should be no l vomiting（呕吐）and no severe headache.

Earlier this year, the British Journal of Sports Medicine published new guidelines for concussions in children and teens. International experts said they should not return to sports or school until fully recovered. The brain also needs a "cognitive rest," they say, by restricting activities like video games, texting and watching TV.

It often take longer than adults to recover from a concussion than adults. The experts say individual progress and not a set time period should always guide a decision to return to play.

The researchers at the -University of California found that children who received CT scans

       A．were likely to suffer brain injuries 

       B．wouldn't have normal mental activity

       C．would lose consciousness now and then 

       D．were likely to develop canter

How many aspects should doctors consider when deciding whether a child under two needs a CT scan?      

       A．Four．     B．Six．       C．Seven．   D．Nine．

What can we learn from the last two paragraphs?

       A．Texting is harmful to patients’ recovery from concussions．

       B．Patients with brain injuries can play many sports．

       C．Adults need a longer time than teens to recover from concussions．

       D．It takes at least a year for individuals with brain injuries to fully recover．

The author of the passage mainly___．

       A．describes the risks of brain injuries

       B．suggests CT scans are of practical use

       C．tells us about the risks of brain injury tests

       D．argues against new guidelines for concussions

A single night of taking the drug Ecstasy (摇头丸) can cause serious brain damage and speed up the start of Parkinson’s disease, scientists say. Just two or three Ecstasy tablets can permanently destroy brain cells that affect movement and reasoning, according to American research that links the drug to Parkinson’s for the first time.

A study by a team at Johns Hopkins University in Baltimore, Maryland, involving squirrel monkeys and baboons (狒狒) found that both species suffered permanent damage to key cells, which are lost in Parkinson’s, after receiving three low doses（剂量）of Ecstasy at three-hour periods.

The study is particularly important because baboons are one of the best animal models for the human brain. George Ricaurte, who led the research, said that the widespread abuse of drug might have caused severe damage. “The most troubling result is that young adults using Ecstasy may be increasing their risk of developing Parkinsonism as they get older.”

Alan Leshner, a former director of the US National Institute on Drug Abuse, said, “This study emphasizes the multi-aspect damage that Ecstasy causes to users. We’ve long known that repeated use damages brain cells. But this study shows that even very occasional use can have long-lasting effects on many different brain systems. It sends an important message to young people: don’t experiment with your own brain.”

Janet Betts, a mother whose teenage daughter Leah died after a single Ecstasy tablet in 1995, said, “This comes as no surprise. But people can’t see the effects at first, and they say it won’t happen to them. We’ll see the symptoms later, just as we have with smoking.”

The article is intended to ______.

   A. explain the bad effects of drugs on people’s health

B. warn young people of the risk of taking the drug Ecstasy

   C. persuade people out of such bad habits as smoking and using drugs

D. tell us the links between the drug Ecstasy and Parkinson’s disease

We know from the passage that a low dose of Ecstasy ______.

   A. won’t cause serious brain damage

   B. can permanently destroy one’s brain cells

   C. will result in immediate symptoms

   D. may bring on Parkinson’s at once

Why are squirrel monkeys and baboons involved in the experiments?

   A. Because their brain is similar to human being’s.

   B. Because these animals usually take drugs.

   C. Because these animals will soon get well after the experiment.

   D. Because there is a model in the animals’ brains.

The underlined word “This” in the last paragraph probably means that ______.

   A. Leah died after a single Ecstasy tablet in 1995

B. taking drug has the same symptoms as smoking

C. occasional use of the drug can have long-lasting effects on the brain systems

D. people have long known that repeated use of the drug damages brain cells

A recent study, published in last week’s Journal of the American Medical Association, offers a picture of how risky it is to get a lift from a teenage driver. Indeed, a 16-year-old driver with three or more passengers is three times as likely to have a fatal accident as a teenager driving alone. By contrast, the risk of death for drivers between 30 and 59 decreases with each additional passenger.

The author also found that the death rates for teenage drivers increased dramatically after 10 p.m., and especially after midnight, with passengers in the car, the driver was even more likely to die in a late-night accident.

Robert Foss, a scientist at the University of North Carolina Highway Safety Research Center, says the higher death rates for teenage drivers have less to do with “really stupid behavior” than with just a lack of driving experience. “The basic issue.” he says, “is that adults who are responsible for issuing licenses fail to recognize how complex and skilled a task driving is.”

Both he and the author of the study believe that the way to mitigate (使……缓解)the problem is to have states institute so-called graduated licensing systems, in which getting a license is a multistage process. A graduated license requires that a teenager first prove himself capable of driving in the presence of an adult, followed by a period of driving with night of passenger restrictions, before graduating to full driving privileges.

Graduated licensing systems have reduced teenage driver crashes, according to recent studies, About half of the states now have some sort of graduated licensing system in place, but only 10 of those states have restrictions on passengers, California is the strictest, with a novice (新手)driver prohibited from carrying any passenger under 20(without the presence of an adult over 25)for the first six months.

Which of the following situations is most dangerous according to the passage?

       A．Adults giving a lift to teenagers on the highway after 10 p.m.

       B．A teenager getting a lift from a stranger on the highway at midnight.

       C．Adults driving with three or more teenage passengers late at night.

       D．A teenager driving after midnight with passengers in the car.

According to Robert Foss, the high death rate of teenage drivers is mainly due to ________.

       A．their frequent driving at night

       B．their lack of driving experience

       C．their improper way of driving

       D．their driving with passengers

According to Paragraph 3．which of the following statements is TRUE?

       A．The licensing authorities are partly responsible for teenagers' driving accidents.

       B．Driving is a skill too complicated for teenagers to learn.

       C．Restrictions should be imposed on teenagers applying to take driving lessons.

       D．Teenagers should spend more time learning to drive.

The most suitable measure to be taken to reduce teenagers' driving accidents is that ________ .

       A．driving in the presence of an adult should be made a rule

       B．they should be prohibited from taking on passengers

       C．the licensing system should be improved

       D．they should not be allowed to drive after 10 p.m.