As an essential part and the largest organ of our body, the skin has many important functions. Therefore, getting burnt can lead to very serious
2 . During space missions, astronauts can experience a loss of some of the inner structural support in their bones. For trips in space lasting at least six months, that loss is equal to about 20 years of aging. Luckily, a new study finds a year back on Earth rebuilds half of the strength lost in the affected bone.
Exercise scientist Leigh Gabel was part of a team that tracked 17 astronauts, each of whom had spent four to seven months in space. The team measured the 3-D structure of bone. They focused on the structure of the tibia (胫骨) and the lower-arm bone. The researchers took images of the bones 3 times—before spaceflight and again six months and one year later when the astronaut s returned home from space. From these pictures, Gabel’s team calculated an astronaut’s bone strength and density (密度) at each of those times.
What did they find through comparison of the pictures? Astronauts in space for less than six months regained their preflight bone strength after a year back on Earth. But those who stayed in space longer suffered permanent hone loss in their tibias. That loss was equal to a decade of aging. The lower-arm bones showed almost no loss. That was likely because these aren’t weight-bearing hones on Earth, Gabel explains. In fact, those arms can get a bigger workout in space than on Earth as astronauts use them to move around their craft by pushing off handles and doors.
“Inereasing weight-lifting exercises in space could help alleviate (缓解) bone loss in the legs,” says Steven Boyd, also in exercise scientist.
“With longer spaceflight, we can expect bigger bone loss—and probably a bigger problem with recovery,” says physiologist Laurence Vico. “Space agencies should also consider other bone health measures, such as nutrition, to reduce bone loss and increase bone formation.”
1. Why did Gabel’s team take pictures at different times?A.To offer evidence for their predictions. |
B.To show their respect for the astronauts. |
C.To compare the changes in the astronauts’ bones. |
D.To find out the proper length of staying in space for astronauts. |
A.A spaceflight in less than half a year does no harm to astronauts. |
B.Astronauts coming back from a spaceflight look much older. |
C.Astronauts can avoid bone loss through doing enough exercise. |
D.There is almost no difference in the astronauts’ lower-arm bones. |
A.People on Earth never suffer bone loss. |
B.The finding of the new study is good news for astronauts. |
C.The 17 astronauts knew the bone loss before their spaceflights. |
D.Astronauts can regain their bone strength as soon as they return to Earth. |
A.How to prevent bone loss in space. |
B.Problems faced by astronauts in space. |
C.Astronauts’ suffering from bone loss in space. |
D.Astronauts’ contributions to the development of science. |
3 . A new study suggests that long periods in space can cause the human heart to shrink (缩小). The study—by a team of American researchers—comes as the U.S. makes plans to build a long-term base on the moon and prepares to send astronauts to Mars.
Part of the study was based on the experiences of the retired astronaut Scott Kelly. The U.S. space agency NASA says that during his career, Kelly spent more time in space than any other American astronaut. One of Kelly’s stays aboard the International Space Station (ISS) lasted 340 days. Researchers from the University of Texas Southwestern Medical Center (UT Southwestern) in Dallas collected and analyzed the physical data during Kelly’s long stay aboard the ISS. The goal was to learn the effects of weightlessness on heart health and performance. The team found that during Kelly’s stay in space, the left ventricle (心室) of his heart shrank about 0.74 grams per week.
Dr. Benjamin Levine is a professor at UT Southwestern. He was the leader of the research. In a statement, he explained that because of the conditions in space, the heart does not have to work as hard to pump (输送) blood uphill from the feet. Over time, this can cause shrinkage. In an effort to keep their hearts and bodies healthy in space, astronauts are required to perform different kinds of exercises throughout their stay.
Reductions in heart size are also seen in patients who spend long periods in bed because they are lying flat and the heart does not have to work as hard to pump. A second part of the study examined data from a long-distance swimmer who spent nearly a year trying to cross the Pacific Ocean. The swimmer, Benoit Lecomte, was chosen because he swam more than 2,800 kilometers over 159 days. Levine says long-distance swimming has similar effects on weightlessness. The study showed that during Lecomte’s swim, his left heart ventricle shrank about 0.72 grams per week.
1. How did the researchers carry out their study?A.By interviewing astronauts. | B.By examining collected information. |
C.By experimenting aboard the ISS. | D.By comparing people in different fields. |
A.Do various exercises. | B.Get regular blood tests. |
C.Stay in space for less time. | D.Stand on their heads sometimes. |
A.A patient spending a long time in bed. | B.An astronaut traveling in space for long. |
C.A long-distance professional swimmer. | D.A well-trained marathon runner. |
A.New Ways to Fight Heart Diseases | B.The U.S. Builds a Medical Center in Space |
C.Long Space Flights Can Shrink the Heart | D.Long-distance Swimming Keeps Your Heart Fit |
4 . Take these easy steps to keep your eyes healthy.
EatWell
Quit Smoking
It makes you more likely to get cataracts (白内障), among many other medical problems. If you’ve tried to kick the habit before only to start again, keep at it.
Use Safety Eyewear
If you use dangerous materials on the job or at home, wear safety glasses. Sports like ice hockey, racquetball, and lacrosse can also lead to eye injury.
Look Away From the Computer Screen
Staring at a computer or phone screen for too long can cause trouble focusing at a distance, dry eyes, headaches, and neck pain. To protect your eyes, you can try the following strategies. Make sure your glasses are up to date and good for looking at a computer screen. Choose a comfortable, supportive chair. If your eyes are always dry, try using artificial (人工的) tears.
A.Wear eye protection. |
B.Rest your eyes every 20 minutes. |
C.Good eye health starts with the food on your plate. |
D.Take tests to see how well your eyes work together. |
E.They can provide general eye care and treat eye diseases. |
F.A well-balanced diet also helps you stay at a healthy weight. |
G.The more times you try to quit, the more likely you are to succeed. |
1. How does the woman probably feel in the beginning?
A.Angry. | B.Anxious. | C.Sad. |
A.She is sick. | B.She hurt her knee. | C.She can’t sleep. |
A.Do some work. | B.Visit his parents. | C.Take the kids to the park. |
A.Doctor and patient. | B.Boss and secretary. | C.Husband and wife. |
A.He hurt his knee. | B.He played football. | C.He did his homework. |
7 . “Tooth loss and gum disease, which is inflammation (发炎) of the tissue around the teeth that can cause shrinkage (萎缩) of the gums and loosening of the teeth, are very common, so evaluating a potential link with brain diseases is incredibly important. Our study found that these conditions may play a role in the health of the brain area that controls thinking and memory, giving people another reason to take better care of their teeth,” said study author Satoshi Yamaguchi, Ph.D. of Tohoku University in Sendai, Japan.
The study involved 172 people with an average age of 67 who did not have memory problems at the beginning of the study. Researchers found that the number of teeth and amount of gum disease was linked to changes in the left hippocampus of the brain. For people with mild gum disease, having fewer teeth was associated with a faster rate of brain shrinkage, which was the same for people with severe gum disease having more teeth. After adjusting for age, researchers found that for people with mild gum disease, the increase in the rate of brain shrinkage due to one less tooth was equal to nearly one year of brain aging. By contrast, for people with severe gum disease, the increase in brain shrinkage due to one more tooth was equal to 1.3 years of brain aging.
“These results highlight the importance of preserving the health of the teeth and not just maintaining the teeth,” Yamaguchi said. Though the study does not prove that gum disease or tooth loss causes diseases like Alzheimer’s, it only shows an association. Yamaguchi added, “Future studies are needed with larger groups of people.” The current experiment involved only a small group of people in one region of Japan, and that too from one particular region of the world.
1. What does Satoshi Yamaguchi’s research focus on?A.The reason for gum disease. |
B.The influence of brain shrinkage. |
C.The advances in memory improvement. |
D.The link between dental health and brain. |
A.Supporting evidence for the research results. |
B.Basic theories and results of a previous research. |
C.A further explanation of the research methods. |
D.The detailed procedures of the scientific research. |
A.Treat a brain problem with replacing teeth. |
B.Frequently visit the dentists to maintain teeth. |
C.Protect gums and teeth in their original good state. |
D.Pull out one of their unique teeth as a study object. |
A.The application in related fields. |
B.The further research in wider range. |
C.The difficulties of making the previous studies. |
D.The suggestions for preventing teeth disease. |
A.Making the wearer feel tired. |
B.Gradually weakening an adult’s eyes. |
C.The loss of vision in children. |
D.Permanent change of the eye structure. |
A.Working hard. | B.Wearing sunglasses. |
C.Watching TV in poor light. | D.Reading in bed. |
A.Ways of choosing eye glasses. |
B.Suggestions of eyesight protection. |
C.Untruths of eye glasses and eyesight. |
D.Proven facts of the benefits of eye glasses. |
9 . If there was an app on your phone that claimed to improve your memory, would you be willing to try it? It’s hard to resist the idea of having a better memory. After all, our memories are delicate and can be affected by various factors such as diseases, injuries, mental health conditions, and aging.
In response to this perceived need, the brain training industry has grown rapidly, offering a wide range of accessible and affordable mental exercises through smartphone and tablet apps. Many researchers have found evidence suggesting that well-designed exercises can improve mental abilities and even lead to better scores on IQ tests. They compare the brain to muscles, suggesting that targeted repetition of memory exercises can strengthen and condition our memory processes, similar to how athletes engage in strength and conditioning by repeatedly exercising specific muscle groups.
In contrast to everyday activities like reading a detailed article or solving a complex puzzle, memory training apps are specifically designed to provide a more challenging workout for the brain. These apps typically involve tasks that require tracking a large number of objects while being distracted by a secondary task, such as mental calculations or exploring a game’s landscape. If this brain training proves effective, it could be beneficial for individuals with brain-related disabilities or those recovering from conditions like cancer.
Critics, though, argue that while the concept is appealing, the overall evidence fails to demonstrate significant improvement in core brain processes. Additionally, despite the claims made by many apps and brain training companies, scientists have yet to identify the key factors that make an intervention truly effective or determine the best approaches to address the diverse needs of individuals seeking help.
While the question is still open to debate, there is evidence suggesting that short-term working memory training can benefit high-functioning individuals, such as college students. However, it’s important to note that brain training, like diet and exercise, is unlikely to have identical effects on every individual.
1. In what way is the brain similar to muscles according to many researchers?A.In testing results. | B.In work processes. |
C.In bodily functions. | D.In training methods. |
A.Detailed. | B.Effective. | C.Demanding. | D.Complicated. |
A.Legal claims. | B.Proven effects. | C.Tailored services. | D.Appealing concepts. |
A.Can our memory be improved? |
B.Does brain training actually work? |
C.What have scientists found about memory? |
D.What does the brain training industry bring? |
1. Who is the woman probably talking to?
A.Her doctor. |
B.Her golf teacher. |
C.Her good friend. |
A.In two weeks. |
B.In three weeks. |
C.In three months. |
A.His leg. |
B.His back. |
C.His shoulder. |