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A Canadian researcher has discovered that sound travels (21) air more than one-half kilometer an hour slower than had been believed. The discovery has surprised many engineers and scientists who learned they had been (22) the wrong speed of sound for many years.The speed of sound in air had been (23) to be three-hundred-thirty-one-point-two-nine meters a second. But Doctor George Wong found, (24) accident, that the speed of sound is only three-hundred-thirty-one-point-one-three meters a second. That is a difference of about sixteen centimeters a second.Doctor Wong is a member of the National Research Council of Canada. He was studying ways to (25) exactly the sound created by microphones. One of his experiments (26) a number he could use to find the speed of sound. He was (27) to learn that the speed of sound was slower than scientists had thought.To explain the difference, Doctor Wong spent eighteen months (28) past test research on the speed of sound. He finally found the (29) of the difference. It was a mathematics mistake (30) in Nineteen-Forty-Two by physicist H-C Hardy.Doctor Wong’s (31) does not mean a big change for the science of sound. This is (32) Doctor Hardy and Doctor Wong measured the speed of sound for what is called" standard air".Standard air exists only (33) thought. It is a way for scientists to agree (34) the same speed of sound. (35) the air around us, standard air always has a temperature of zero degrees Celsius and the same atmospheric pressure (36) the air at sea level. Standard air always has same amounts of nitrogen, oxygen, carbon dioxide and (37) gases. And in standard air, the speed of sound does not change.The change in the new speed of sound is (38) small to affect the work of most sound scientists and engineers. But scientists say Doctor Wong’s discovery may (39) improve instruments (40) use the speed of sound to measure very short distances. 26().
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A Canadian researcher has discovered that sound travels (21) air more than one-half kilometer an hour slower than had been believed. The discovery has surprised many engineers and scientists who learned they had been (22) the wrong speed of sound for many years.The speed of sound in air had been (23) to be three-hundred-thirty-one-point-two-nine meters a second. But Doctor George Wong found, (24) accident, that the speed of sound is only three-hundred-thirty-one-point-one-three meters a second. That is a difference of about sixteen centimeters a second.Doctor Wong is a member of the National Research Council of Canada. He was studying ways to (25) exactly the sound created by microphones. One of his experiments (26) a number he could use to find the speed of sound. He was (27) to learn that the speed of sound was slower than scientists had thought.To explain the difference, Doctor Wong spent eighteen months (28) past test research on the speed of sound. He finally found the (29) of the difference. It was a mathematics mistake (30) in Nineteen-Forty-Two by physicist H-C Hardy.Doctor Wong’s (31) does not mean a big change for the science of sound. This is (32) Doctor Hardy and Doctor Wong measured the speed of sound for what is called" standard air".Standard air exists only (33) thought. It is a way for scientists to agree (34) the same speed of sound. (35) the air around us, standard air always has a temperature of zero degrees Celsius and the same atmospheric pressure (36) the air at sea level. Standard air always has same amounts of nitrogen, oxygen, carbon dioxide and (37) gases. And in standard air, the speed of sound does not change.The change in the new speed of sound is (38) small to affect the work of most sound scientists and engineers. But scientists say Doctor Wong’s discovery may (39) improve instruments (40) use the speed of sound to measure very short distances. 22().
A new report by the U.N. AIDS organizations finds the global AIDS epidemic is worsening. The agency says more people in all regions around the world are becoming infected with HIV, the virus which causes AIDS. UNAIDS reports significant progress has been made in providing treatment for larger numbers of AIDS victims and in achieving greater political and financial commitments in the fight against the fatal disease. Despite this, the report says none of these efforts has been enough to prevent the spread of HIV/AIDS.Last year, the report notes five million people became newly infected with HIV. That is more people than any previous year. Currently, it says, more than 38 million people are living with the disease. UNAIDS Senior Adviser Karen Stanecki. says Asia, with 60 percent of the world’s population, is home to some of the fastest-growing epidemics in the world. In 2003 alone, she says, more than one million people became infected with HIV."Equally alarming, we have only just begun to witness the full impact of AIDS on African societies as infections continue to grow and people are dying in large numbers," said Ms. Stanecki. "The scale of the problem in Africa is well-documented, with over 25-million infections. If we do not act now,60 percent of today’s 15 year olds will not reach their 60th birthday."The report says the Caribbean is the hardest hit region in the world after Africa. It also finds the HIV/AIDS epidemic is continuing to expand in Eastern Europe and Central Asia, mainly due to intravenous drug users.UNAIDS says infections also are on the rise in the United States and Western Europe. It blames this largely on the widespread availability of anti-AIDS drugs, which it says has made some people in these wealthy countries complacent. UNAIDS Director of Monitoring and Evaluation, Paul De Lay, acknowledges that around the world prevention programs are reaching fewer than one in five people who need them. Nevertheless ,he says there has been a dramatic increase in prevention activities for young people and several other successes as well."In Africa, for instance ,60 percent of children have access to AIDS education both in primary and secondary schools, "said Mr. De Lay. "That is a huge increase from the late 1990’s. In highly vulnerable groups like sex workers, we are seeing a real success story in Africa. Thirty-two percent of sex workers who are identified have access to HIV prevention and there is a large increase in condom use in this population."The report says global spending on AIDS has increased greatly, but, more is needed. It estimates $12 billion will be needed by next year, and $ 20 billion by 2007, for prevention and care in developing countries. The United Nations says AIDS funding has increased sharply in recent years, in part due to the U.S. government’s global AIDS initiative. But it says still, globally less than half the money needed is being provided. What's the conclusion about global spending on AIDS in this new UN report()
Fireworks are a big part of Fourth of July celebrations in the United States, as hundreds of thousands of Americans enjoyed public pyrotechnic displays across the country Sunday night to celebrate the U.S. birthday. The holiday throws the spotlight on another annual campaign ,an effort to completely ban consumer fireworks in the United States.As Americans around the country watched July Fourth fireworks celebrations, debate has been simmering about whether individuals should be allowed to buy fireworks to celebrate privately. Seven U.S. states prohibit sales of all consumer fireworks. A coalition of groups, led by James Shannon, president of the non-profit fire safety group, the National Fire Protection Association, says that ban should be extended to include the entire United States. "Those fireworks axe inherently dangerous products," he said. "There might be another problem with some of them being designed defectively, so that they are particularly dangerous. But even when they’re designed to do what they’re supposed to do and do it, they can be very, very dangerous products. "Other members of the coalition include the International Fire Chiefs Association and the American Academy of Pediatrics, which has focused on the dangers fireworks pose to children.The U.S. Consumer Product Safety Commission, an independent federal regulatory agency, says fireworks-related accidents in the United States in 2002 killed four people and injured about 8, 800 others in the United States. About haft of the people injured were children, a fact pointed to by Mr. Shannon. "I don’t think serious injury is as American as apple pie, if it’s avoidable. And particularly, if we’re talking about children, thousands and thousands of children, "he said.But fireworks have strong defenders, such as the American Pyrotechnic Association, which says that they are becoming more and more popular in the United States. Officials with the association say that fireworks use in the United States has more than tripled since 1990, to nearly 100-kilograms in 2003. And Ann Crampton, spokeswoman for the National Council on Fireworks Safety, says fireworks are a big part of Fouth of July celebration and their use should not be banned. But Ms. Crampton also says people should exercise care when using them. "We know that millions of people are going to be celebrating with fireworks on the Fourth of July, "she said. "It’s become part of a symbol of this country. Many thousands of people, millions of people, enjoy going to public displays. But there are also people that like to be hands-on and do it themselves in their backyards. We feel they can be safe and they can be injury-free if they choose the right product, know what to choose,what to stay away from."Most of the fireworks sold in the United States come from China. According to the U.S. Census Bureau, Chinese fireworks imports to the United States in 2003 amounted to more than $157-million. Ms. Crampton says the U.S. pyrotechnics industry has been working with Chinese manufacturers to make fireworks safer. "And about 15 years ago, a group was formed, called the American Fireworks Standards Laboratory, to work with Chinese manufacturers, to make sure that the product that they were making meets the safety standards that are required here," she said.The National Fire Protection Association has been lobbying against consumer fireworks sales since 1910. Their efforts are not going to be made any easier by Consumer Product Safety Commission statistics showing that the number of fireworks-related deaths and injuries in the United States has actually fallen in recent years. What is the author's attitude in this article()
A Canadian researcher has discovered that sound travels (21) air more than one-half kilometer an hour slower than had been believed. The discovery has surprised many engineers and scientists who learned they had been (22) the wrong speed of sound for many years.The speed of sound in air had been (23) to be three-hundred-thirty-one-point-two-nine meters a second. But Doctor George Wong found, (24) accident, that the speed of sound is only three-hundred-thirty-one-point-one-three meters a second. That is a difference of about sixteen centimeters a second.Doctor Wong is a member of the National Research Council of Canada. He was studying ways to (25) exactly the sound created by microphones. One of his experiments (26) a number he could use to find the speed of sound. He was (27) to learn that the speed of sound was slower than scientists had thought.To explain the difference, Doctor Wong spent eighteen months (28) past test research on the speed of sound. He finally found the (29) of the difference. It was a mathematics mistake (30) in Nineteen-Forty-Two by physicist H-C Hardy.Doctor Wong’s (31) does not mean a big change for the science of sound. This is (32) Doctor Hardy and Doctor Wong measured the speed of sound for what is called" standard air".Standard air exists only (33) thought. It is a way for scientists to agree (34) the same speed of sound. (35) the air around us, standard air always has a temperature of zero degrees Celsius and the same atmospheric pressure (36) the air at sea level. Standard air always has same amounts of nitrogen, oxygen, carbon dioxide and (37) gases. And in standard air, the speed of sound does not change.The change in the new speed of sound is (38) small to affect the work of most sound scientists and engineers. But scientists say Doctor Wong’s discovery may (39) improve instruments (40) use the speed of sound to measure very short distances. 33().
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