Multitasking(多任务) affects the brain, research suggests, and it could be damaging your career. A new study found that men and women who frequently used several types of technology at the same time had less grey matter(灰质) in a key part of the brain.

University of Sussex researchers said: “Using mobile phones, laptops and other media devices at the same time could be changing the structure of our brains.” Worryingly, the part of the brain that shrinks is involved in processing emotion. The finding follows research which has linked multitasking with a poor attention, depression, anxiety and lower grades at school.

The researchers began by asking 75 healthy men and women how often they divided their attention between different types of technology. This could mean sending a text message while listening to music and checking emails, or speaking on the phone while watching TV and surfing the web. The volunteers were then given brain scans which showed they had less of grey matter. The study, published in the journal PLOS ONE, is the first to make a link between multitasking and the structure of the brain.

Researcher Kep Kee Loh said: “Media multitasking is becoming more common in our lives today and there is increasing concern about its influences on our cognition(认知) and social-emotional well-being.” He added that more research is needed to prove that multitasking shrinks the brain. This is because it is also possible that people with less grey matter are more drawn to using lots of devices at the same time. Scientists have previously proved brain structure can be changed on long exposure to new environments and experience. Other studies have shown that training---such as learning to juggle or taxi drivers learning the map of London -- can increase grey-matter densities(密度) in certain parts.

Why do men die earlier than women? The latest research makes it known that the reason could be that men’s hearts go into rapid decline when they reach middle age. The largest study of the effects of ageing on the heart has found that women’s longevity(长寿) may be linked to the fact that their hearts do not lose their pumping power with age.

“We have found that the power of the male heart falls by 20-25 percent between 18 and 70 years of age,” said the head of the study, David Goldspink of Liverpool John Moores University in the UK.

“Within the heart there are millions of cells that enable it to beat. Between the age of 20 and 70, one-third of those cells die and are not replaced in men,” said Goldspink. “This is part of the ageing process.” What surprises scientists is that the female heart sees very little loss of these cells. A healthy 70-year-old woman’s heart could perform almost as well as a 20-year-old one’s.

“This gender difference might just explain why women live longer than men,” said Goldspink.

They studied more than 250 healthy men and women between the ages of 18 and 80, focusing on healthy persons to remove the confusing influence of disease.

The team has yet to find why ageing（衰老）takes a greater loss on the male heart, said Goldspink.

The good news is that men can improve the health of their heart with regular exercise. Goldspink stressed that women also need regular exercise to prevent their leg muscles becoming smaller and weaker as they age.

The 1990s saw great changes in the way people communicate. People could send mail without going to the   (1)  , and go shopping without leaving home.   (2)   like email and download became part of people’s vocabulary. The cause of this great change was the   (3)  .

The idea for the Internet began in the early 1960s in   (4)  . The Department of Defense (美国国防部) wanted to   (5)   their computers together in order to   (6)   private information. In 1969, the ARPA net(an early form of the Internet) first connected the   (7)   at four American universities. One computer successfully   (8)   information to another. In 1972, scientists shared ARPA net   (9)   the world. They created a   (10)   to send person-to-person messages using ARPA net. This was the   (11)   of email.

Over the next few years, there was a lot of progress made in the world of computing,   (12)   most people were not using the Internet. Then, in the 1980s, personal computers became more   (13)  . In the early 1990s,   (14)   important things happened:the birth of the World Wide Web in 1991, and the creation of the   (15)   Web browser（浏览器）in 1993.The web made it   (16)   to find information on the Internet, and to move from place to place   (17)   links. The Web and browser made it possible to see information as a website with pictures, sound, and words.

Today,   (18)   of people connect to the Internet to send email, visit websites, or store information on servers.   (19)   are now an important part of our lives and are changing   (20)   we learn, work, shop, and communicate.

If you think that running marathons will help you live a long and healthy life，new research may come as a shock．According to a recent scientific study，people who do a very strenuous workout are as likely to die as people who do no exercise at all．

Scientists in Denmark have been studying over 1，000 joggers and non-joggers for 12 years．The death rates from the sample group indicate that people who jog at a moderate pace two or three times a week for less than two and a half hours in total are least likely to die．The best speed to jog at was found to be about 5 miles per hour．The research suggests that people who jog more than three times a week or at higher speeds of over 7 mph die at the same rate as non-joggers．The scientists think that this is because strenuous exercise causes structural changes to the heart and arteries(动脉)．Over time，this can cause serious injuries．

Peter Schnohr，a researcher in Copenhagen，said，“If your goal is to decrease risk of death and improve life expectancy，jogging a few times a week at a moderate pace is a good strategy．Anything more is not just unnecessary，and it may be harmful．”

The implications of this are that moderate forms of exercise such as tai chi，yoga and brisk walking may be better for us than“iron man”events，triathlons and long-distance running and cycling．According to Jacob Louis Marott，another researcher involved in the study，“You don’t actually have to do that much to have a good impact on your health．And perhaps you shouldn’t actually do too much”．

People in theUSthought Ebola was only a disease, accompanied with fever and found inAfricaat the beginning.  (1)  then a man from west Africa died from Ebola at a hospital in Dallas, Texas. And two nurses   (2)   for him became infected(感染) with the virus, which made the US government publish new guidelines to   (3)   health workers．

Top American  (4)  have repeatedly said that most people have little chance of being infected．Experts have  (5)   that Ebola can only be spread through infected person’s body fluids — like blood．But it   (6)   many Americans are  (7)  what they have heard．

A recent survey found more than 80 percent of Americans believe that Ebola can be spread in many   (8)  , including air forced through the nose or mouth. The Harvard School of Public Health   (9)   the findings. The study also showed that most adults fear there will be a(n)  (10)  of Ebola in the United States soon.

  (11)   survey found that more than 70 percent of Americans would support calls to   (12)   travel to and from Ebola-affected parts ofAfrica.

Thomas Frieden heads the U.S．Centers for Disease Control and Prevention．When asked whether   (13)   officials had considered a travel ban, Mr．Frieden had  (14)    to say：“We won’t be able to check travelers for   (15)  when they leave or when they arrive. We won’t be able, as we do   (16)  , to take a detailed history to see if they were   (17)   when they arrive. When they   (18)   , we wouldn’t be able to impose quarantine（强加隔离）as we now can if they have high-risk touch.”

Last week, President Barack Obama urged Americans not to   (19)   what he called “ panic or fear ”.

This week，the administration announced that all travelers reaching the United States from some African nations are  (20)   to pass through one of five airports.

    It has proved pretty hard for doctors to treat a damaged brain. Without enough blood, the brain lives for only three to five minutes. More often the doctors can’t fix the damage. Sometimes they are afraid to try something to help because it is dangerous to work on the brain. The doctors might make the person worse if he operates on the brain.

    Dr. Robert White, a famous professor and doctor, thinks he knows a way to help. He thinks doctors should make the brain very cold. If it is very cold, the brain can live without blood for 30 minutes. This gives the doctor a longer time to do something for the brain.

    Dr. White tried his idea on 13 monkeys. First he taught them to do different jobs, and then he operated on them. He made the monkeys’ blood go through a machine. The machine cooled the blood.

    Then the machine sent the blood back to the monkeys’ brains. When the brain’s temperature was 10℃, Dr. White stopped the blood to the brain. After 30 minutes he turned the blood back on. He warmed the blood again. After their operations the monkeys were like they had been before. They were healthy and busy. Each one could still do the jobs the doctor had taught them.

a．send the cooled blood back to the brain. b．stop the blood to the brain.

c．have the blood cooled down.          d．operate on the brain.

Laughter is the best medicine. It helps those who cannot work out become healthy. We can easily recognize laughter, but what exactly is it?

Experts say that  (1)   out loud helps improve your fitness. This is  (2)   laughter strengthens the heart and the lungs. Besides, a good laugh can  (3)   your muscles. As you laugh, they become  (4)  . After you laugh, these muscles start to relax. According to the research, this  (5)   is very useful for people with breathing problems. Some parts of the body are exercising. It’s a massage(按摩) inside the body!

Laughter  (6)   makes us feel happy. Experts say that the positive feelings produced  (7)   laughter not only make us feel a sense of  (8)   but also helps us reduce pain.

The next time you feel upset  (9)   disappointed, do not worry. Enjoying a funny comedy or reading some jokes will  (10)   your negative feelings and make you feel much better. Meanwhile, laughter measures your ability to handle the world around you. If you can laugh when you are afraid, you will be able to survive your troubles. If you are in control and sure of yourself, then you can enjoy a happy life.

Since the 1970s，scientists have been searching for ways to link the brain with computers. Brain Computer Interface(BCI) technology could help people with disabilities send commands to machines.

Recently，two researchers，Jose Millan and Michele Tavella from the Federal Polytechnic School in Lausanne，Switzerland，demonstrated (展示) a small robotic wheelchair directed by a personˈs thoughts.

In the laboratory，Tavella operated the wheelchair just by thinking about moving his left or right hand. He could even talk as he watched the vehicle and guided it with his thoughts.

“Our brain has billions of nerve cells. These send signals through the spinal cord (脊髓) to the muscles to give us the ability to move. But spinal cord injuries or other conditions can prevent these weak electrical signals from reaching the muscles.” Tavella says. “Our system allows disabled people to communicate with external world and also to control devices.”

The researchers designed a special cap for the user. This head cover picks up the signals from the scalp (头皮) and sends them to a computer. The computer interprets the signals and commands the motorized wheelchair. The wheelchair also has two cameras that identify objects in its path. They help the computer react to commands from the brain.

Prof. Millan，the team leader，says scientists keep improving the computer software that interprets brain signals and turns them into simple commands. “The practical possibilities that BCI technology offers to disabled people can be grouped in two categories: communication，and controlling devices. One example is this wheelchair.”

He says his team has set two goals. One is testing with real patients，so as to prove that this is a technology they can benefit from. And the other is to guarantee that they can use the technology over long periods of time.