They said highly anxious rats which were kept had very low levels of a brain chemical called fibroblast growth factor 2 or FGF2, compared with rats that were more relaxed. But when they improved the anxious rats' living conditions -- giving them new toys to explore and a bigger cage to live in -- levels of this brain chemical increased and they became less anxious. "The levels of this brain chemical increased in response to the experiences that the rats were exposed to. It also decreased their anxiety". Javier Perez of the University of Michigan said in a telephone interview. "It made them behave the same way as the rats that were relaxed", he said. In a former study of people who were severely depressed before they died, the team found the gene that makes FGF2 was producing very low levels of the growth factor, which is known primarily for organizing the brain during development and repairing it after injury. Perez thinks the brain chemical may be a marker for genetic vulnerability to anxiety and depression. But it can also respond to changes in the environment in a positive way, possibly by preserving new brain cells. While both the calm and anxious rats produced the same number of new brain cells, these cells were less likely to survive in the high-anxiety rats, the team found. Giving the rats better living conditions or injecting them with FGF2 helped improve cell survival. "This discovery may pave the way for new, more specific treatments for anxiety that will not be based on sedation , but will instead fight the real cause of the disease," Dr. Pier Vincenzo Piazza from France said in a statement. What's the main influence of the new discovery? A) Doctors won't use any medicine to cure anxiety. B) Doctors may find new medicine for anxiety. C) Doctors will find the real cause of anxiety. D) Doctors may treat anxiety more efficiently.
D
When I was fourteen, I earned money in the summer by cutting lawns , and within a few weeks I had built up a body of customers. I got to know people by the flowers they planted that I had to remember not to cut down, by the things they lost in the grass or struck in the ground on purpose. I reached the point with most of them when I knew in advance what complaint was about to be spoken, which request was most important. And I learned something about the measure of my neighbors by their preferred method of payment: by the job, by the month--or not at all. Mr. Ballou fell into the last category, and he always had a reason why. On one day, he had no change for a fifty, on another he was flat out of checks, on another, he was simply out when I knocked on his door. Still, except for the money apart, he was a nice enough guy, always waving or tipping his hat when he'd seen me from a distance. I figured him for a thin retirement check, maybe a work-related injury that kept him from doing his own yard work. Sure, I kept track of the total, but I didn't worry about the amount too much. Grass was grass, and the little that Mr. Ballou's property comprised didn't take long to trim . Then, one late afternoon in mid-July, the hottest time of the year, I was walking by his house and he opened the door, mentioned me to come inside. The hall was cool, shaded, and it took my eyes a minute to adjust to the dim light. "I owe you," Mr Ballou said, "but..." I thought I'd save him the trouble of thinking of a new excuse. "No problem. Don't worry about it." "The bank made a mistake in my account," he continued, ignoring my words. "It will be cleared up in a day or two. But in the meantime I thought perhaps you could choose one or two volumes for a down payment. He gestured toward the walls and I saw that books were stacked everywhere. It was like a library, except with no order to the arrangement. "Take your time," Mr. Ballou encouraged. "Read, borrow, keep, or find something you like. What do you read?" "I don't know." And I... From what he said to the author we can guess that Mr. Ballou _ . A) read all books twice B) did not do much reading C) read more books than he kept D) preferred to read hardbound books
C
Long long ago, there was an old merchant who had three sons. "To which one shall I leave my fortune?" he wondered. "It must be to the cleverest son. But which one is the cleverest?" He called his three sons to him. "Here is some money," he told them, "you must each take one coin to buy something that will fill this room. Anyone who can do this shall have my fortune." "It is a big room," said the eldest son. "One coin will not buy very much," said the second son. But the youngest son said nothing. He stood and thought, and then he smiled, "Come, brothers," he said, "let us go to the market." The eldest son bought straw with his coin. But one coin bought only a bit of straw. Even when he had spread it as much as he could, the straw covered only a corner of the room. The second son bought sand with his coin. But one coin bought only a bit of sand. Even when he had spread it as much as he could, the sand covered only half of the floor. "What did you buy?" the eldest son angrily asked the youngest son. "You don't have any straw." "Yes, what did you buy?" the second son asked angrily. "You don't have any sand." "I bought this," said the youngest son. "A candle!" cried his brothers. "What good is a candle?" "Watch", said the youngest son. He lit the candle, and all at once the room was filled from wall to wall, from ceiling to floor. It was filled with light! "Although you are the youngest, you are indeed the cleverest of my sons," the old merchant said. And that is how, the old merchant left his fortune to his youngest son, the one who could fill a room with light. Who would get father's fortune? A) The oldest son. B) The richest son. C) The cleverest son. D) The silliest son.
C