Read the following article and select the best answer. Article: Autism spectrum disorder is a developmental disability. People with autism have trouble communicating and with social skills. The U.S. Centers for Disease Control and Prevention says the person also might repeat some behaviors and not want change in their daily activities. Some people with the condition need a lot of help. Others need less. CDC officials say autism affects one in every 68 children in the United States. More boys than girls are believed to have the condition. But the number of cases appears to be growing. It is unclear whether the growing number shows a real increase or comes from more knowledge about this disorder. Symptoms of autism Common signs of autism include trouble making eye contact and a delay in learning how to speak. Some people with severe autism never learn how to talk. Many people with autism also have difficulty understanding facial expressions and the feelings of others. They also have trouble making friends of the same age. Doctors have learned how to recognize autism, but much is still unknown about its causes. Researchers at Harvard University have come closer to finding answers. They found that women exposed to the highest levels of fine particulate air pollution late in their pregnancies are two times more likely to give birth to a child with autism. The findings appeared in Environmental Health Perspectives -- a publication of the National Institute of Environmental Health Sciences. The study found that the women who were around high levels of fine particulate matter air pollution were at highest risk of having an autistic child. The increased risk of these women was two times that of women who lived in areas with low levels of fine particulate pollution. The researchers found that the timing of exposure to pollution was important. They found no increased risk of autism in children whose mothers were around high levels of pollution before becoming pregnant. And the study found air pollution does not seem to increase the risk of children developing autism after they are... Question: What's the main idea of the passage _ ? - what is autism spectrum disorder - the reasons of autism - autism and air pollution - how to treat autism
autism and air pollution

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Read the following article and select the best answer. Article: For some reason Dodger did not want to enter London during daylight, so it was nearly eleven o'clock at night when they got near the centre. Oliver had never seen a dirtier or more miserable place. The streets in this district were narrow and muddy, and there were terrible smells everywhere. Children wandered around even at this time of night, in and out of the many shops, playing and screaming. The pubs were full of people fighting, and big, evil-looking men stood in the doorways or at dark corners. Oliver almost wanted to run away, but just then Dodger pushed open a door and pulled Oliver into a dark hall. "Who's there?" a voice cried out. "It's me," said Dodger. The faint light of a candle appeared in the hall. "Who's the other one?" "A new friend." They went up some dark and broken stairs. Oliver could hardly see where he was going, but Dodger seemed to know the way, and helped Oliver up. They entered a room with walls that were black with age and dirt. In front of the fire was a table with a candle stuck into a bottle of beer, and an old man, with a horribly ugly face and red hair, stood next to the fire cooking. He was wearing a dirty old coat and seemed to divide his attention between his cooking and a number of silk handkerchiefs, which were hanging near the fire. There were several rough beds in the room. Four or five boys, about the same age as Dodger, sat round the table, smoking and drinking like middle-aged men. They all looked up when Dodger and Oliver entered. "This is him, Fagin," Dodger said to the old man. "My friend Oliver Twist." Fagin smiled and shook Oliver's hand. Then all the young gentlemen came up to him and shook both his hands very hard, especially the hand which held his few possessions. One of the boys was particularly kind. He even put his hands in Oliver's pockets so that Oliver would not have to empty them himself when he went to bed. The boys would probably have been even more helpful, but Fagin hit them on their heads and shoulders until they left Oliver alone. "We're very... Question: Why did Dodger enter London late at night? - Because Dodger was too weak to walk until. - Because Dodger was afraid of being seen by others. - Because Dodger and Oliver wanted to play in the countryside. - Because Dodger was afraid of Fagin and did not want to go home.
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Because Dodger was afraid of being seen by others.

Read the following article and select the best answer. Article: When Iain Douglas-Hamilton first started studying elephants in Africa,he had to invent ways of tracking the big animals. Over the course of 40 years in the field, the zoologist learned how to fly airplanes and use some high-tech means to follow their movements. He also learned how to get out of the way fast. "I learned how to climb trees very quickly," says Dr. Douglas-Hamilton, winner of the 2010 Indianapolis Prize. As co-founder of Save the Elephants, he has also learned to be an activist, author, and politician. When Douglas-Hamilton left Tanzania, in East Africa, in 1970 to study at Oxford University in Britain, he left behind "an elephants' paradise ."But when he returned in 1972, the country's national parks looked more like a war zone. Douglas-Hamilton often found more dead elephants than living ones. Dr. Douglas-Hamilton now lives in Kenya with his wife, Oria, who co-founded Save the Elephants. Together they have written two books, "Battle for the Elephants" and " Among the Elephants". During the height of the ivory poaching ,Douglas-Hamilton flew in small planes, helping bring back elephants in Uganda from the edge of extinction. He's been repeatedly shot at and has survived plane crashes, floods and diseases. He fought for years for a worldwide ban on ivory sales, which finally took effect in 1989. Douglas-Hamilton pioneered the scientific study of elephant social behavior. Among his discoveries: Elephants have a society controlled by female elephants and travel in families. In 2009, he worked to save a rare group of desert elephants in Mali from the worst dry weather in Mali's history. There have been other successes, particularly in East and Southern Africa. Douglas--Hamilton has proposed the idea of a mobile national park, where the protected land would follow elephants as they travel. No country has yet accepted it. Even after decades of research, Douglas-Hamilton still enjoys the company of elephants. "I love to sit with them and be with them, "he says. "I have the greatest joy just to be... Question: Douglas-Hamilton did the following to protect elephants EXCEPT _ . - building mobile national parks - saving desert elephants in Mali - founding Save the Elephants - demanding a ban on ivory sales
building mobile national parks