The world's oceans are slowly getting more acidic, say scientists. The researchers from California say the change is taking place in response to higher levels of carbon dioxide in the atmosphere. The lowering of the waters' pH value is not great at the moment but could pose a serious threat to current marine life if it continues, they warn. Ken Caldeira and Michael Wickett, from the Lawrence Livermore National Laboratory, report their concerns in the journal Nature. Increasing use of fossil fuels means more carbon dioxide is going into the air, and most of it will eventually be absorbed by seawater. Once in the water, it reacts to form carbonic acid. Scientists believe that the oceans have already become slightly more acidic over the last century. But these researchers have tried to predict what will happen in the future by combining what we know about the history of the oceans with computer models of climate change. "This level of acidity will get much more extreme in the future if we continue releasing CO2 into the atmosphere," said Dr Caldeira. "And we predict amounts of future acidity will exceed anything we have seen over the last several hundred million years, let alone perhaps after rare catastrophic events such as asteroid impacts ." If carbon dioxide release continues unabated , ocean pH could be reduced by as much as 0.77 units, the authors warn. It is not ly clear what that means for marine life, however. Most organisms live near the surface, where the greatest pH change would be expected to occur, but deep-ocean lifeforms may be more sensitive to pH changes. Coral reefs and other organisms whose skeletons or shells contain calcium carbonate may be particularly affected, the team speculate. They could find it much more difficult to build these structures in water with a lower pH. In recent years some people have suggested deliberately storing carbon dioxide from power stations in the deep ocean as a way of curbing global warming. But Dr Caldeira said that such a strategy should now be... According to Dr Caldeira, _ . A) the future situation of the amount of acidity is extremely serious B) ocean absorption of carbon dioxide is a good thing C) scientists may predict climate changes with computer models D) more oil fuels will be used in the near future
A
(Question)
American this year will swallow 15,000 tons of aspirin, one of the safest and most effective drugs invented by man. The most popular medicine in the world today, it is an effective pain reliever. Its bad effects are ly mild and it is cheap. For millions of people suffering from arthritis . It is the only thing that works. Aspirin, in short, is truly the 20th-century wonder drug. It is also the second largest suicide drug and is the leading cause of poisoning among children. It has side effects that, although ly mild, are largely unrecognized among users. Although aspirin was at first sold by a German company in1899, it has been around much longer than that. Hippocrates, in ancient Greek, understood the medical value of the leaves and tree bark which today are known to contain salicylates , the chemical in aspirin. During the 19thcentury, there was a great deal of experimentation in Europe with this chemical, and it led to the introduction of aspirin. By 1915, aspirin tablets were available in the United States. A small quantity of aspirin (two-grain tablets) relieves pain and inflammation. It also reduces fever by interfering with some of the body's reactions. The passage is written to _ . A) suggests us using more aspirin B) reminds us of the side effects of aspirin C) gives us a whole view of aspirin D) discusses the good effects of aspirin
(Answer)
C
Ques: A severe heatwave sweeping India, with temperatures of almost 44oC, the highest in 52 years, has killed at least 80 people this month, officials said on Sunday. The hot weather, which officials say would continue over northern, north-western and central India in the next 48 hours, also may have some impact on wheat production, exporters and flour-mill associations said. New Delhi recorded a maximum temperature of 43.7oC on Saturday, indicating a hot summer in the next two months in the nation's capital and other parts of northern and eastern India. The highest temperature in the past 24 hours was 47oC at Ganganagar city, in Rajasthan state. Summer temperatures have been 4oC-6oC above normal over most parts of northern and central India since March, weather officials said. In the eastern state of Orissa, authorities have decided to shut down schools from next Tuesday, advancing the annual summer holiday. Authorities said they were investigating reports of 53 deaths from various parts of the state. "District collectors have been asked to investigate and submit reports on other deaths," Bhimsen Gochhayat, a government official said. Other deaths were reported from northern state of Uttar Pradesh and central Madhya Pradesh states. India is expected to produce about 82 million tons of wheat in 2009-2010, but there could be a shortage of 1-1.5 million tons due to the heatwave, said Veena Sharma, Secretary General of the Roller Flour Millers Federation of India. "Most of the harvesting is over, but there definitely will be a slight shortage of 1-1.5 million tons due to the extreme weather conditions," she told Reuters. India is relying on an abundant wheat crop to make up for a 14.2% drop in rice output, the major summer-sown food grain, _ by the worst monsoon in 37 years last year. Weather officials say with summer temperatures in India set to remain above average, there were hopes of heavy rains at the start of the monsoon season that will help early sowing of rice, soybeans and lentils. The purpose of the passage is _ . A) to tell a piece of news of a heatwave B) to record the highest temperature in India C) to report the deaths in the heatwave D) to inform people of a drop of rice output
Ans: A
This is a true story from Guyana. One day, a boy took a piece of paper from a box. He made a paper ball and pushed it into his nose. He couldn't get it out. He ran crying to his mother. His mother couldn't get the paper out, either. A week later, the paper was still in the boy's nose. His nose began to have a bad smell. So his mother took the boy to a hospital. The doctor looked up at the child's nose, but she couldn't get the paper out. She said she had to cut the boy's nose to get the paper out. The boy's mother came home looking sad. She didn't want her child to have his nose cut. The next day she took the boy to her friend Sidney who lived in a house with an old lady called May. May wanted to see the child, so the child let her look up his nose. "Yes, I can see it," May said. "It will be out soon." As she spoke, she shook some black pepper on the child's nose. The child gave a mighty sneeze and the paper flew out. His mother was surprised. May told his mother to take the boy to the seaside for a swim, for the salt water would go up his nose and stop the bad smell. So the lucky boy didn't have to go to the hospital to have his nose cut. The paper ball stayed in the boy's nose for _ . A) at most seven days B) less than seven days C) more than seven days D) exactly seven days,
C