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- In addition to getting them vaccinated (...spread of the virus.
- The flu is a highly (1) respiratory illness. It turns up year after year with devastating consequences, all caused by a most elusive virus. The influenza, or flu virus, is a recurring nightmare. It causes more than 36,000 deaths in the U.S each year, and was responsible for some of history’s deadliest pandemics. Like other viruses, the flu virus is a parasite. The viral agent itself called, a virion, is made of ribonucleic acid or RNA surrounded by proteins. The flu virus uses two proteins to attack its host, hemagglutinin and neuraminidase or the HA and NA proteins. The HA protein attaches a virus to a cell and lets it in. Once the virus is inside, it multiplies. Then the NA protein cuts this (2) swarm loose, sending it off to infect more cells. This triggers the immune system to bombard the swarm and to destroy infected tissue throughout the respiratory system. Unfortunately, this response can also inadvertently lead to death through organ failure or secondary infections like (3) pneumonia. The flu virus has been nearly impossible to eradicate, largely due to its uncanny ability to mutate. Since just 2004, more than 5,000 different strains of the influenza virus have been sequenced. Those that affect humans are categorized as Types A, B or C, with Type A strains being the most capable of unleashing a pandemic. Influenza A viruses mutate more rapidly, allowing them to adapt to new hosts and even cross species. Avian flu and Swine flu, for instance, are two strains of Type A viruses that through mutations, can be transmitted from birds and pigs to humans. One of the deadliest flu (4) was caused by one such virus. Between 1918 and 1919, the Spanish flu infected a third of the global population and killed up to 50 million people worldwide. Called H1N1, this particular strain of virus likely came from birds. The threat of another influenza pandemic remains. In the meantime, scientists are constantly monitoring the flu virus and developing seasonal (5) to create our best line of defense.
- Complete the following passage using words from the list A-L in the box below. A. sore B. severe C. connect D. infect E. pandemic F. epidemics G. commonly H. Unfortunately I. initially J. expected K. suspected L. runny Influenza, (1) called "the flu," is an illness caused by RNA viruses (Orthomyxoviridae family) that (2) the respiratory tract of many animals, birds, and humans. In most people, the infection results in the person getting a fever, cough, headache, and malaise (tired, no energy); some people also may develop a (3) throat, nausea, vomiting, and diarrhea. The majority of individuals has flu symptoms for about 1-2 weeks and then recovers with no problems. However, compared with most other viral respiratory infections, such as the common cold, influenza (flu) infection can cause a more (4) illness with a mortality rate (death rate) of about 0.1% of people infected with the virus. The above is the usual situation for the yearly occurring "conventional" or "seasonal" flu strains. However, there are situations in which some flu outbreaks are severe. These severe outbreaks occur when a portion of the human population is exposed to a flu strain against which the population has little or no immunity because the virus has become altered in a significant way. These outbreaks are usually termed (5) . Unusually severe worldwide outbreaks (pandemics) have occurred several times in the last hundred years since influenza virus was identified in 1933. By an examination of preserved tissue, the worst influenza (6) (also termed the Spanish flu or Spanish influenza) occurred in 1918 when the virus caused between 40-100 million deaths worldwide, with a mortality rate estimated to range from 2%-20%. In April 2009, a new influenza strain against which the world population has little or no immunity was isolated from humans in Mexico. It quickly spread throughout the world so fast that the WHO declared this new flu strain (first termed novel H1N1 influenza A swine flu, often later shortened to H1N1 or swine flu) as the cause of a pandemic on June 11, 2009. This was the first declared flu pandemic in 41 years. Fortunately, there was a worldwide response that included vaccine production, good hygiene practices (especially hand washing), and the virus (H1N1) caused far less morbidity and mortality than was (7) and predicted. The WHO declared the pandemic's end on Aug. 10, 2010, because it no longer fit into the WHO's criteria for a pandemic. Researchers identified a new influenza-related viral strain, H3N2, in 2011, but this strain has caused only about 330 infections with one death in the U.S. Since 2003, researchers identified another strain, H5N1, a bird flu virus, that caused about 650 human infections. This virus has not been detected in the U.S. and easily spreads among people in contrast to other flu strains. (8) , people infected with H5N1 have a high death rate (about 60% of infected people die). Currently, H5N1 does not readily transfer from person to person like other flu viruses.
- Which<br/>one of following is most accurate?() A: HCV<br/>is transmitted through blood,but HDV not B: Both<br/>HBV and HCV can establish a chronic carrier state C: There<br/>is an effective vaccine against HCV but not against HDV D: Both<br/>HCV and HDV are defective virus E: Both<br/>HCV and HDV can be cultured artifially
- Many researchers believe that light can affect both your physical and your （1） .
内容
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Usually, the influenza virus is spread through the air from (1) or (2).
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Good hygiene routines and healthy habits can help you live happily.
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[音频]In addition to spoken language, all human beings also use body language to help them _________________ their ideas. The use of body language, which includes both ___________ with your hands and ___________________,such as a smile, is ____________.
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The ____1____（novelty）coronavirus(冠状病毒) has much in common ____2___ seasonal flu.They are both viral infections, share similar symptoms and crucially(关键地） can spread from human to human. In the midst of flu season in much of the northern hemisphere, ____3___(tell) the difference between the two will be vital in stopping its spread. Human coronaviruses, of which there are four, can cause respiratory (呼吸道)infections similar to flu: while many symptoms are mild, both can lead to pneumonia（肺炎） and become lethal（致命的）. ___4___, the novel coronavirus is more serious than __5__ "typical influenza infection,(流感)"says Ian Jones, a professor of virology at the University of Reading. "This virus appears to go___6___(far) down into the lungs than would generally be the case. Therefore, it will give you___7___ (symptom) of pneumonia(肺炎): the lungs becoming flooded, they don't function very well and the patient gets into breathing difficulty." While the mortality rates and symptoms of flu and novel coronavirus may end up being similar, humans' ability ___8____(fight) off the viruses differs greatly. Humans have naturally built up antibodies to seasonal flu and annual vaccines____9____(develop) to fight it. During a pandemic (流行病), which the new coronavirus has the potential to become, "there is no immunity (免疫性) in the population so you have potential for a ___10___(globe) spread," warns Jones.
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Which of the following can be inferred from the passage A: There are useful viruses as well as harmful ones. B: Many virus checking software is free of charge. C: Even if you take the advice, your computer may still be infected with viruses. D: Shut down your computer whenever there is a virus.