【推荐1】Exercise may help to safeguard the mind against depression through previously unknown effects on working muscles, according to a new study involving mice.  

Mental health experts have long been aware that even mild, repeated stress can contribute to the development of depression and other mood disorders in animals and people. Scientists have also known that exercise seems to cushion against depression. But precisely how exercise, a physical activity can lessen someone’s risk for depression, a mood state, has been mysterious. So for the new study, researchers at the Karolinska Institute in Stockholm studied the brains and behavior of mice in a complicated and novel fashion.

We can’t ask mice if they are feeling cheerful or in low spirits. Instead, researchers have pictured certain behaviors that indicate depression in mice. If animals lose weight, stop seeking out a sugar solution when it’s available — because, probably, they no longer experience normal pleasures — or give up trying to escape from the cold-water zone just freeze in place, they are categorized as depressed. And in the new experiment, after five weeks of frequent but low-level stress, such as being lightly shocked, mice displayed exactly those behaviors. They became depressed. 

The scientists could then have tested whether exercise blunts (延缓) the risk of developing depression after stress by having mice run first. But, frankly, from earlier research, they wanted to know how, so they bred pre-exercised mice. A wealth of earlier research by these scientists and others had shown that aerobic exercise, in both mice and people, increases the production within muscles of an enzyme (酶) called PGC-1alpha. The Karolinska scientists suspected that this enzyme somehow creates conditions within the body that protect the brain against depression. Then, the scientists exposed the animals, which without exercising, were in high levels of PGC-1alpha to five weeks of mild stress. The mice responded with slight symptoms of worry. But they did not develop depression. They continued to seek out sugar and fought to get out of the cold-water zone. Their high levels of PGC-1alpha appeared to make them depression-resistant. Finally, to ensure that these findings are relevant to people, the researchers had a group of adult volunteers complete three weeks of frequent endurance training, consisting of 40 to 50 minutes of moderate cycling or jogging. The scientists conducted muscle biopsies (活体检查) before and after the program and found that by the end of the three weeks, the volunteers’ muscle cells contained substantially more PGC-1alpha than at the study’s start. The finding of these results, in the simplest terms, is that “you reduce the risk of getting depression when you exercise,” said Maria Lindskog, a researcher at the Karolinska Institute.

1. The researchers at the Karolinska Institute in Stockholm conducted the new study hoping to know______.

A．if exercise cushions against depression

B．what can lead to depression in animals and people

C．if stress can contribute to the development of depression

D．how exercise contributes to reducing someone’s risk for depression

2. We can infer from the new experiment conducted by researchers at the Karolinska Institute that mice are depressed except when ______.

A．they stand still in place

B．they stop searching for the sugar water

C．they attempt to escape from the cold-water zone

D．they can’t experience normal pleasures any longer

3. Researchers asked a group of adult volunteers to complete three weeks of frequent endurance training in order to ______.

A．know if exercise can help to safeguard the mind against depression

B．know if they can endure 40 to 50 minutes of moderate cycling or jogging

C．confirm the findings above are also relevant to people

D．ensure they can lose weight after moderate cycling or jogging

4. It can be concluded from the passage that______.

A．the enzyme called PGC-1alpha helps to ease depression

B．athletes are more likely to develop depression than ordinary people

C．the mice with high levels of PGC-1alpha are easier to develop depression

D．in the past mental health specialists didn’t know exercise could help reduce depression

【推荐2】It is nothing new that most of us know that physical activities lead to better health. But for the first time in these years, the United States government has changed its guidance on how much exercise people need to stay healthy and when they should start.

The new guidance states that children as young as three need to be physically active. Earlier guidelines used to begin at six. The most important time for children to begin exercising is between the ages of three and five. Boys and girls in this age group need at least three hours of exercise every day. That could be light activities, moderate (中等的) activities, or even strong activities.

Doctors say it is important to start at a young age. They add that from birth to the age of five, a child's brain develops more than at any other time in life. These developments have a lasting influence on a child's ability to learn and to succeed in school and in life. Children who start exercising at a young age are more likely to develop healthy behavior that will continue into adulthood. However, Dr. Giroir, who works at the U.S. Department of Health and Human Services, does not suggest putting a five-year-old child on a "treadmill (跑步机)"or other exercise equipment. He thinks that simply giving children the time and space to play actively as they normally would is enough.

The new guidelines say that children aged between 6 and 17 get at least one hour of moderate to strong exercise a day. Most of this exercise should be aerobic exercise (有氧运动)，such as biking, swimming or running. Aerobic activities can strengthen (加强)the heart and lungs by making them work hard for several minutes or more. Exercise should also include muscle- and bone-strengthening activities, such as climbing trees or playing sports. Experts suggest that children get this kind of exercise at least three times a week.

1. What's the best age to begin exercising?

A．Under three.

B．Above six.

C．Between three and five.

D．Between six and seventeen.

2. From the text, we know a five-year-old child should ______ .

A．run on the treadmill every day

B．do aerobic exercise regularly

C．be given more free time to play

D．do muscle-strengthening activities

3. What will happen to the body if a boy does aerobic exercise often?

A．His heart and lungs will be stronger.

B．His brain will develop faster.

C．He will be big-boned.

D．He will grow higher.

4. What can be the best title for the text?

A．The earlier exercise guidance is given, the better

B．New exercise instruction: Start earlier

C．Children need more exercise

D．Life lies in movement.

【推荐1】Although computer technology is often necessary today, using a pen or pencil activates (激活) more areas of your brain than a keyboard does. You can remember more by handwriting, according to a new study.

The potential benefits of handwriting for memory have been debated for some time. The new study set out to answer one question: How does handwriting compare to using a keyboard when it comes to remembering new information?

In all 24 people took part in the study. Researchers asked each of them to write with a pen and then each was also asked to type on a keyboard. While performing these tasks, each volunteer wore a cap that held electrodes (电极) next to their head. It looked somewhat like a hair not fitted with 256 sensors. Those sensors recorded those people’s brainwaves (脑波). The electrodes noted which parts of the brain turned on during each task. And they showed that writing turned on memory areas in the brain while typing didn’t.

Audrey van der Meer, the new study’s leader. says this suggests that when we write by hand, we remember better. “This is because writing needs complex (复杂的) movements that activate more area s of the brain. The increased brain activity gives the brain more ‘hooks’ to hang your memories on,” she explains. Van der Meer also points out that writing by hand is related to visual notetaking. “Rather than typing blindly, the visual notetaker has to think about what is important to write down. Then, key words can be interlinked by boxes, arrows and small drawings,” she adds.

This study does not suggest stopping using digital products. In fact, its authors point out, computers and other devices with keyboards have become necessary in modern society. Keyboarding can especially benefit those with certain special needs (such as if they have trouble using their hands) and typing beats writing when it comes to speed, they add.

1. Why were people tested in the study asked to wear caps?

A．To record their brainwaves.	B．To inform them of their tasks.
C．To allow them to focus on writing.	D．To protect their heads like hair nets.

2. What does, Audrey van der Meer try to explain?

A．Why handwriting is more complex than typing.	B．Why the brain works when it comes to learning.
C．Why handwriting helps remember information.	D．Why keywords are helpful to visual notetaking.

3. What do the authors of the study think of typing?

A．It sets free people’s hands.	B．It is not worth recommending.
C．It remains important and helpful.	D．It is more challenging than writing.

4. What’s the main idea of the text?

A．How can you remember new information?	B．Handwriting benefits health in the long run.
C．Should typing take the place of handwriting?	D．Handwriting is better for memory than typing.

【推荐2】By 2050, a completely new type of human evolve as a result of extremely new technology, behavior, and natural selection. This is according to Cadell Last, a researcher at the Global Brain Institute, who claims mankind is undergoing a major “evolutionary transition”.
In less than four decades, Mr. Last claims we will live longer, have children in old age and rely on artificial intelligence to do ordinary and boring tasks. This shift is so significant, he claims, it is comparable to the change from monkeys to apes, and apes to humans. “Your 80 or 100 is going to be so radically different than your grandparents,” Mr. Last says, who believes we will spend much of our time living in virtual reality. Some evolutionary scientists believe this age could be as high as 120 by 2050.
Mr. Last claims humans will also demonstrate ____________, according to a report by Christina Sterbenz in Business Insider. This refers to something known as life history theory which attempts to explain how natural selection shapes key events in a creature’s life, such as reproduction. It suggests that as brain sizes increase, organisms need more energy and time to reach their full potential, and so reproduce less.
Instead of living fast and dying younger, Mr. Last believes humans will live slow and die old. “Global society at the moment is a complete mess,” he told MailOnline. “But in crisis there is opportunity, and in apocalypse (启示) there can be transformation. So I think the next system humanity creates will be far more sophisticated, fair, and abundant than our current civilization.”
“I think our next system will be as different from the modern world, as our contemporary world is from the medieval (中世纪的) world. The biological clock isn't going to be around forever,” he added, and said that people could pause it for some time using future technology.
The change is already happening. Today, the average age at which a woman in Britain has her first baby has been rising steadily stands at 29. 8. In the US, just one percent of first children were born to women over the age of 35 in 1970. By 2012, that figure rose to 15 percent.
“As countries become socio-economically advanced, more and more people, especially women have the option to engage in cultural reproduction,” Mr. Last added. And as well as having more child-free years to enjoy leisure time, he believes artificial intelligence will make up the need for low-skill jobs. We may also spend a large amount of time living in virtual reality. “I’m not quite sure most people have really absorbed the implications of this possibility,” Mr. Last said.
His views are detailed in a paper, titled “Human Evolution, Life History Theory, and the End of Biological Reproduction" published Current Aging Science.
1. According to Cadell Last, a completely new type of human will appear because of ______.
① artificial intelligence ② new technology ③ natural selection ④ mundane tasks
⑤ behavior

A．②③⑤

B．①②③

C．③④⑤

D．①②⑤

2. Which statement is compared by Mr. Last to the change from monkeys to apes, and apes to humans?

A．We have diseases and die young.

B．We spend less time in virtual reality.

C．We give birth to a child when we are young.

D．We use intelligent robots to do everyday housework.

3. The underlined words in the third paragraph most probably mean “______”.

A．Reproduction.

B．Reproduce less.

C．Natural selection shapes key events.

D．Organisms need more energy and time to ripen.

4. In the next system Mr. Last explained we can infer that ______.

A．women are engaged in careers or hobbies instead of giving birth to babies

B．women are engaged in playing computer games rather than working

C．women are engaged in cultural reproduction in place of men

D．women are engaged in living in virtual reality without options

【推荐3】A team of Japanese scientists has discovered genes that enable rice to survive high water, providing hope for better rice production in lowland areas that are affected by flooding.

The genes, called SNORKEL genes, help rice grow longer stems to deal with higher water levels. Deepwater rice generally produces low-yield (低产的) rice plants. But the researchers report they have succeeded in introducing the genes to rice varieties that are higher-yield.

According to the report, as water levels rise, accumulation of the plant hormone (激素) ethylene (乙烯) makes the SNORKEL genes start working, making stem growth more rapid. When the researchers introduced the genes into rice that does not normally survive in deep water, they were able to rescue the plants from drowning.

Motoyuki Ashikari, who headed the project, said his team is hoping to use the gene on long grain rice widely used in Southeast Asia to help stabilize production in flood areas where rice with the food-resistant gene is low in production — about one-third to one-quarter that of regular rice. “Scientifically the gene that we found is rare but clear proof of a biological ability to adapt to a difficult environment,” he said. “It’s a genetic strategy specifically to survive flooding.”

High water levels in rice field can be a serious problem. In some areas, rains can cause water levels to rise dangerously high during the growing season and flash flooding can fully cover plants for days or even weeks.

Rice is a main food for billions, and while productivity has increased dramatically since the 1960s, yields must be doubled to meet projected requirements by 2050. More than 30 percent of Asian and 40 percent of African rice land is either lowland field or deep water field.

Laurentius of Utrecht University said the study is significant because high-yield rice varieties cannot survive extremes of floods. “The introduction of these genes into high-yield varieties, using advanced breeding strategies, promises to improve the quality and quantity of rice.” he said.

1. What can readers know about SNORKEL genes?

A．They make rice become ripe within a shorter time.

B．They make rice grow tall enough to survive in deep water.

C．They help rice grow stronger whatever the areas and the climate.

D．They prevent rice from being attacked by various insects.

2. What will happen to the rice with the special gene, according to the text?

A．It will be helpful for Northeast Asia.

B．It will be softer than regular rice.

C．It will be widely planted all over the world.

D．It will increase the production of rice.

3. What does the underlined word “projected” in Paragraph 6^th probably mean?

A．Loose.

B．Remarkable.

C．Planned.

D．Complicated.

4. What is the purpose of the text?

A．To introduce a scientific research finding.

B．To analyze a scientific experiment result,

C．To discuss a plant developing effort.

D．To guide the development of agriculture.