Faces that activate the same regions of the brain again and again are more likely to be remtembered. Practice makes perfect when it comes to remembering things, but exactly how that works has long been a mystery. A study published in Science recently indicates that reactivating neural patterns over and over again my store items into the memory. People find it easier to recall things if material is presented repeatedly at well-spaced intervals rather than all at once. For example, you're more likely to remember a face that your've seen on some occasions over a few days than one that you've seen once in one long period. One reason that a face linked to many different contexts -such as school, work and home- is easier to recognize than one that is associated with just one setting, such as a party, could be that there are some ways to access the memory. This idea, called the encoding variability hypothesis ,was proposed by psychologists about 40 years ago. Each different context or setting activates a clear set of brain regions; the hypothesis suggests that it is these differing neural responses that improve the memory. But neuroimaging research led by Russell Poldrack, a scientist at the University of Texas. Austin, now suggests that the opposite is true--items are better remembered when they activate the same neural patterns with each exposure. Poldrack's team measured brain activity in 24 people using functional magnetic resonance imaging. The subjects saw 120 unfamiliar faces, and each one repeated four times at varying intervals during the scan. One hour later, they were shown the faces again, mixed with 120 new ones, and asked to rate the familiarity of each. The researchers then looked at the brain responses that had been recorded when the subjects wee first shown the faces, focusing on 20 brain regions associated with visual perception and memory. Face that were later recognized evoked similar activation patterns at each repetition in nine of the regions, particularly those associated... The passage is mainly about _ . A) how the brain works B) why some memories fade away C) the encoding variability hypothesis D) the neuroimaging research
D
(Question)
Have you ever wondered when dogs first became "man's best friend" and the world's favourite pet? If you have then you're not alone. When and where dogs first began living side-side with humans are questions that have stirred hot debate among scientists. There are a few hard facts that all agree on. These include that dogs were once wolves and they were the first animal to be domesticated by humans. They came into lives some 15000 years ago, before the dawn of agriculture. Beyond that, there is little agreement. The earliest bones found that are unquestionable dogs and not wolves date from 14,000 years ago. However, 30,000-year-old skulls have been discovered in France and Belgium that are not pure wolf and some scientists think could be dogs. With such puzzling evidence, many scientists are now turning to DNA to find out when and where dogs were first domesticated. In one research project, tens of thousands of blood samples have been taken from street dogs around the world. The plan is to compare them with those of wolves. It's even possible to analyse DNA from ancient bones. Tiny pieces of the 30,000-year-old skulls mentioned earlier are currently being studied, and another DNA study has already shown that ancient dogs preserved in the Alaskan ice-fields evolved from Asian wolves, not American ones. Indeed, the ancient DNA may turn out to be more informative than the DNA of living dogs. Because dogs have accompanied humans around the world for thousands of years, their current distribution may tell us very little of their origins. This is why different groups of scientists believe that dogs variously originated in eastern Asia, Mongolia, Siberia, Europe or Africa. But why were the animals domesticated in the first place? The most recent theory is that dogs domesticated themselves, initially living in and around our ancient villages to eat any food thrown out. Today, this is a way of life still shared by three -quarters of a billion unowned dogs worldwide. How did scientists determine the origins of the ancient dogs found in Alaska? A) By examine the animals' DNA B) By analyzing the age of their bones C) By studying the shape of their skulls D) By comparing them with modern dogs
(Answer)
A
Ques: The host poured the tea into the cup and placed it on the small table in front of his guests,who were a father and his daughter,and put the lid on the cup with a clink.Obviously thinking of something.he hurried into the inner room,leaving the thermos on the table.His two guests heard a chest of drawers opening and rustling. They remained sitting in the sitting room,the ten-year-old daughter looking at the flowers outside the window,the father just about to take his cup,when the crash came,right there in the sitting room.Something was hopelessly broken. It was the thermos,which had fallen to the floor.The girls looked over her shoulder suddenly,shocked, staring. It was mysterious;neither of them had touched it,not even a little bit.True.it hadn't stood steadily when their host placed it on the table,but it hadn't fallen then. The crash of the thermos caused the host,with a box of sugar cubes in his hand,to rush back from the inner room.He looked foolishly at the steaming floor and blurted out. "It doesn't matter! It doesn't matter!'' The father started to say something.Then he said in a low voice,"Sorry I touched it and it fell." "It doesn't matter,"the host said. Later,when they left the house,the daughter said,"Daddy,did you touch it?'' "No.But it stood so close to me." "But you didn't touch it.I saw your reflection in the window .You were sitting perfectly still." The father laughed."Then how would you explain the cause of its fall?" "The thermos fell by itself , The floor is uneven. It wasn't steady when Mr. Li put it there. Daddy,why did you say that?" "That won't do,girl.It sounds more acceptable when I say I knocked it down.There are things which people accept less true it sounds." The daughter was lost in silence for a while.Then she said,"Can you explain it only this way?" "Only this way."her father said. Which statement is a possible main idea of this story? A) People seldom tell the truth. B) You can't always make people believe the truth C) If you try to defend yourself,people will believe you. D) People never believe others.
Ans: B
Ques: Mr and Mrs Smith had always spent their summer holidays in New Jersey in the past, staying in a small inn at the foot of a hill. One year, however, Mr. Smith made a lot of money in his business, so they decided to go to London and stay at a really good hotel while they went touring around that famous city. They flew to London and arrived at their hotel late one evening. They expected that they would have to go to bed hungry, because in that small inn in New Jersey, no meals were served after seven. They were therefore surprised when the man who received them in the hall asked whether they would take dinner there that night. "Are you still serving dinner?" asked Mr Smith. "Yes, certainly, sir," answered the man. "We serve it until half past nine." "What are the times of meals then?" asked Mr Smith. "Well, sir," answered the man, "We serve breakfast from seven to half past eleven in the morning, lunch from twelve to three in the afternoon, tea from four to five, and dinner from six to half past nine." "But that hardly leaves any time for us to see the sights of London!" said Mrs Smith. When the man told them the times of meals at the hotel, Mrs Smith felt _ . A) disappointed B) excited C) delighted D) satisfied
Ans:
A