题目内容
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
【小题1】D
【小题1】B
【小题1】A
【小题1】C
解析:
略
阅读快车系列答案What happens inside the skull of a soccer player who repeatedly heads a soccer ball? That question motivated a challenging new study of the brains of experienced players that has caused discussion and debate among soccer players, and some anxiety among those of us with soccer-playing children.
For the study, researchers at the Albert Einstein College of Medicine in New York selected 34 adults, men and women. All of the volunteers had played soccer since childhood and now competed year-round in adult soccer leagues. Each filled out a detailed questionnaire developed especially for this study to determine how many times they had headed a soccer ball in the previous year, as well as whether they had experienced any known concussions (脑震荡) in the past.
Then the players completed computerized tests of their memory and other learning skills and had their brains scanned, using a complicated new M.R.I. technique which can find structural changes in the brain that can’t be seen during most scans.
According to the data they presented at a Radiological Society of North America meeting last month, the researchers found that the players who had headed the ball more than about 1,100 times in the previous 12 months showed significant loss of white matter in parts of their brains involved with memory, attention and the processing of visual information, compared with players who had headed the ball fewer times.
This pattern of white matter loss is “similar to those seen in traumatic (外伤的) brain injury”, like that after a serious concussion, the researchers reported, even though only one of these players was reported to have ever experienced a concussion.
The players who had headed the ball about 1,100 times or more in the past year were also generally worse at recalling lists of words read to them, forgetting or fumbling the words far more often than players who had headed the ball less.
【小题1】The passage is most probably a______.
| A．news report | B．research report |
| C．story for soccer players | D．text for doctors |
| A．Computerized test. | B．Questionnaire.. |
| C．Scanning. | D．M.R.I. technique. |
| A．significant effect on brain | B．little effect on one’s brain |
| C．nothing to do with the brain injury | D．one’s memory improved |
| A．remembering | B．misunderstanding |
| C．recalling | D．missing |