Wisdom teeth are normally the last teeth to appear.This usually happens when people are in their late teen years or early twenties,in other words,when they are older and wiser. Wisdom teeth can grow into place normally and never cause a problem.But often there is not enough room for them in the mouth;they might crowd other teeth.Sometimes they even push sideways through the gums . An impacted wisdom tooth is one that fails to completely rise through the gums.Wisdom teeth that only partly break through can leave space for bacteria to enter around the teeth.Infection is a risk in these cases. Wisdom teeth that are not well lined and become impacted are often removed.The American Dental Association says removal is generally advised when wisdom teeth only partly break through the gums.Removal is also advised if there is a chance that wisdom teeth ate poorly lined.The best time to remove is before the teeth cause any problems or pain.Young adults are the best candidates for wisdom teeth removal. But why do we have wisdom teeth if we often need to get them removed?One theory has to do with our diets.Scientists say the diet of ancient humans probably required more chewing teeth.Life was probably a little rougher on the teeth back then,too.So it was good to have extras. We can learn from the passage that _ . A) impacted wisdom teeth have the risk of getting infected B) ancient humans need chewing teeth because of their happy life C) older adults are the best candidates for wisdom teeth removal D) more chewing teeth are needed for the diet of modern humans
A
High childcare costs are putting British mothers off going out to work. It really is that simple. Eurostat figures show that 66 per cent of mothers in the UK work, less than France (72 per cent), Denmark (86 per cent), the Netherlands (78 per cent) or Germany (69 per cent). This not only damages Britain's economic prosperity--it limits women's careers and squeezes family incomes. It would be fine if this is the choice parents want to make, but it isn't. Half of those surveyed want to go to work and the expense of childcare is one of the key reasons they couldn't. Despite claims made by Labour about childcare, a forthcoming report by the Institute for Public Policy Research (IPPR) confirms the true legacy of their time in government. They left behind a childcare system with high costs to parents, variable quality and patchy coverage, despite soaring government spending. British parents now face the highest childcare bills in the world after Switzerland. In the Eighties and Nineties under Mrs Thatcher and John Major, the picture was very different. Mothers in England were more likely to go out to work than their Dutch or German counterparts. But the position has reversed, despite a huge rise in public spending. So why does the British Government spend more on childcare than France or Germany, even though the costs given to parents are sky-high? As always, under the previous government, money was frittered away without adequate focus on improving quality. Instead of clear and transparent funding, four separate funding streams were created, skewing the market and confusing parents and providers alike. The majority of the money was given away in cash benefits; so much of it did not get through to the front line. The IPPR report points out that continental systems, in countries such as Germany, France, Denmark and the Netherlands, manage to deliver better value for money. What all of these systems have in common is a focus on quality, with greater flexibility and autonomy given to local providers. They... We can learn from the passage that _ . A) in the Eighties and Nineties, mothers in the UK were likely to work B) there is a prejudice against mothers in the UK employment market C) most of the mothers surveyed in the UK don't want to work D) the percentage of mothers who work in the UK is the lowest in the world
B
Q: Now, we know that if we do not get enough vitamins, we are at risk of developing a number of diseases. As a result, vitamin supplements ,though expensive, are popular with people who worry that they are not getting enough vitamins from the foods they eat. But contrary to what many people think, medical experts have found little evidence that most supplements do anything to improve health or protect against disease. In fact, medical experts warn that taking too many of some vitamins can be harmful. For example, too much vitamin E can cause bleeding. People should discuss what vitamins they take with their doctors, as some vitamins can produce harmful side effects when mixed with medicines. Experts, however, do say that sometimes vitamins can help prevent disease. People who know they lack a particular vitamin should take vitamin supplements. Some older adults, for example, may not have enough vitamin B-twelve. This is because, as people get older, their body loses its ability to take it from foods. Also, people who spend much time inside may need some extra vitamin D as the skin makes this vitamin from sunlight. Different vitamins are found in different foods. Vitamin A is found in fish liver oil. It also is in the yellow part of eggs. Sweet potatoes, carrots and other darkly color1ed fruits and vegetables contain substances that the body can change into vitamin A. Vitamin B-twelve is found in green leafy vegetables and other foods, like fruits. Vitamin K can be found in pork products. In fact, for most people, a balanced diet can ensure enough of the vitamins our bodies need. So, it is important for us to eat a mixture of foods every day to ensure that we get enough vitamins our bodies need. For people who lack Vitamin B-twelve, they can eat more from _ . A) sweet potatoes B) green leafy vegetables C) pork products D) eggs
A: B
*Question*
In many romantic movies or TV shows one scene always appears. It involves a handsome man standing outside a young woman's window, singing a love song to her to win her over. However, trying to woo a female with songs is not just something that humans do. A few animals sing love songs as well. Birds and elephants are romantic but the latest animal to _ a female might surprise you--it is the humble mouse. You may find it odd to find out that mice sing. We do not hear them because the frequency of their voice is so high. In fact, scientists have known for some time that male mice make special sounds to females, but it has always been assumed that the sounds are produced instinctively and randomly, with little thought going into the process. But new research suggests otherwise. When male mice with different voices were put in a cage together, scientists found that they would gradually change their pitches to sound like one another. But when a female mouse was put in the cage with two males, one male would change his pitch to match the other. "It was usually the smaller animal changing the pitch to match the larger animal," professor Erich Jarvis, leader of the study, from Duke University, US, told BBC News. This ability, known as vocal learning, is rare in the natural world. It had been thought to be limited to some birds, such as parrots--as well as whales and dolphins. The latest findings challenge the long-held opinion that mice cannot learn to adapt their voices. Scientists also found the part of the brain that controls the mice's singing ability. In the experiment, they damaged the cells in this part of the mice's brain and found that the animals couldn't keep their songs in pitch or repeat them any more. This also happened when the mice became deaf. Jarvis said that this finding had changed his understanding of the way mice make sound. "In mice we find that the pathways that are at least modulating these vocalizations are in the forebrain, in places where you actually find them in humans,"... Which of the following is proven wrong by the latest discovery? A) The frequency of mice's voice is so high that it's impossible for humans to hear it. B) When male mice make special sounds to females they can't control the sounds. C) Birds and elephants are both romantic animals that are good at expressing love. D) Animals like mice are smart even though they often make sounds randomly.
**Answer**
B