题目内容
Why does John want to buy a bike？
查看答案
搜索结果不匹配？点我反馈
更多问题
As concern over Alzheimer's disease grows, more Americans are turning to expensive and potentially unsafe supplements that claim to enhance memory. But prevention of age-related memory loss may be no further away than your refrigerator, and no more expensive than a bag of groceries, experts say. With the aging population of baby boomers in the United States, more research is being done than ever before on diseases such as Alzheimer's and other forms of dementia. Scientists are developing a better understanding of why memories fade, and along the way they are finding new ways to combat the decline.
For one thing, research increasingly suggests that diet may be important in preventing Alzheimer's. As the brain ages, it loses the ability to protect itself from the barrage of commonplace dangers it faces every day, particularly inflammation and oxidation, a process which allows damaging free radicals to attach themselves to cells.
While it's not entirely clear what causes Alzheimer's disease, amyloid plaque——a goopy, fibrous substance akin to fur balls in the brain——plays a key role. As the plaque builds up, it causes more oxidation and inflammation, and begins to kill off brain cells. In addition, brain cells often stop communicating with each other as people age, making it harder for the brain to process thoughts, retain short-term memory and create new cells.
"Old neurons are like old married couples——they don't talk to each other very much any- more. They just sit in the room with the remote and stare at the TV," says Dr. James Joseph, director of the Neuroscience Lab at the Human Nutrition Research Center on Aging at Tufts University in Boston. While research in the field of aging and nutrition is still in its infancy, scientists have found that diet may help minimize the brain's sensitivity to oxidation and inflammation, as well as improve brain cells' ability to communicate with each other.
One of the most intriguing areas of research involves the role of antioxidants, potent chemicals in plants that protect against free radicals, highly active molecules that damage cells. Antioxidants are what give fruits and vegetables their bright colors. Plants produce these chemicals to protect themselves from environmental insults, such as pollution, and when humans eat plants, they also reap the protective benefits.
We can infer from the passage that people suffering from Alzheimer's disease will _________.
_________ exerted by tornadoes that they have been known to lift railroad locomotives off
听力原文： Finance Ministers from 18 Asian nations are considering proposals to pay for developing roads, airports and water supplies during the next 10 years. The Ministers from the Asia-Pacific Economic Cooperation Group say they need many thousands of millions of dollars for such development. The organization is holding its yearly meeting through Sunday in Serbul, the Philippines.
Large sums of money are needed for the development of all the following EXCEPT ______
SECTION A CONVERSATIONS
Directions: In this section you will hear several conversations. Listen to the conversations carefully and then answer the questions that follow.
听力原文：Man: Hew! This rowing is hard work. Let's have the boat toward the old light house now.
Woman: Good idea. We can rest there a while and eat our lunch. Then we can climb to the top platform. where the light is before we visit the museum at the base of the light house tower.
Man: Whenever I come out here, I think about the family who used to live on the little island and take care of the light every night. What a lonely life that must have been.
Woman: Yeah. To help ships find their way along shoreline at night, they had to constantly make sure that the windows up around the light were clean and free of ice and snow.
Man: Dirty soot must have been a problem. Didn't they bum candles up there？
Woman: No they use electricity, I think.
Man: I understand the United States Coast Guard takes care of the most modem lighthouses.
Woman: Yeah, but the lights are automatic nowadays. The lighthouse is still a friendly sight at night though.
Man: Here we are. This lighthouse is the friendliest sight I have seen today. I am exhausted.
What are the two speakers doing while having this conversation ？
微信支付 
支付宝支付