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  3. Part Ⅱ Reading Comprehension (Skimming and Scanning) Directions: In this part, you will have 15 minutes to go over the passage q

Part Ⅱ Reading Comprehension (Skimming and Scanning) Directions: In this part, you will have 15 minutes to go over the passage q

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问题                                        Part Ⅱ Reading Comprehension (Skimming and Scanning)
Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1.
   For questions 1～7, mark
   Y (for YES )            if the statement agrees with the information given in the passage;
   N (for NO )             if the statement contradicts the information given in the passage;
   NG (for NOT GIVEN)      if the information is not given in the passage.
   For questions 8～10, complete the sentences With the information given in the passage.
                                 Influenza
    Influenza is caused by a virus transmitted from one person to another in droplets coughed or sneezed into the air. It is characterized by cold like symptoms plus chills, fever, headaches, muscle aches, and fatigue. Most people recover completely in about a week.
    In addition to humans, influenza occurs in pigs, horses, and several other mammals (哺乳动物) as well as in certain wild and domesticated birds. At least some influenza viruses can jump from one species to another. For example, in late 1997 a strain of the influenza virus in chickens began to infect humans in Hong Kong, leading to a massive effect to remove the strain.
    Many millions of people develop the flu each year. In most years less than 1 percent of those infected die. Nonetheless, this translates into large numbers. The United States Centers for Disease Control and Prevention (CDC) estimates that influenza causes more than 20,000 deaths in the United States each year; combined, influenza and pneumonia (肺炎)are among the nation’s ten leading causes of death. During epidemics and pandemics, death rates soar. The influenza pandemic that occurred between 1918 and 1919--the worse on record--killed about 500,000 people in the United States and more than 20 million people worldwide.                              
    Symptoms and diagnosis
    Influenza is an acute disease with a rapid onset and obvious symptoms. After the influenza virus invades a person’s body, an period of one or two days passes before symptoms appear. Classic symptoms include sore throat, dry cough, stuffed or runny no, se, chills, fever with temperatures as high as 39℃, aching muscles and joints, headache, loss of appetite, occasional nausea and vomiting, and fatigue. For most people flu symptoms begin to subside after two to three days and disappear in seven to ten days. However, coughing and fatigue may persist for two or more weeks.
    Death from influenza itself is rare. But influenza can worsen underlying medical conditions, such as heart or lung disease. Invading influenza viruses produce inflammation (发炎) in the lining of the respiratory tract, damage that increases the risk that secondary infections will develop. Common complications include bronchitis, sinusitis, and bacterial pneumonia, occurring most frequently in the elderly, people on chemotherapy (化学疗法),  and people with acquired immunodeficiency syndrome (AIDS) or another disease that compromises the immune system. If properly treated, these complications seldom are fatal.
    Because influenza is so common and exhibits standard symptoms, doctors often diagnose the illness based on the season and whether flu cases have recently been reported in the area. TO prove a diagnosis of influenza in a patient, the virus must be isolated from the person’s nasal or cough secretions or blood and identified under a microscope.
    Treatment and prevention
    There is no specific cure for influenza. Recommended treatment usually consists of bed rest and increased intake of fluids until fever and other symptoms lessen in severity. Certain drugs have been found effective in lessening flu symptoms, but medical efforts against the disease focus chiefly on prevention by means of vaccines that create immunity.
    Vaccines
    A flu vaccine consists of greatly weakened or killed flu viruses, or fragments of dead viruses. Antigens (抗原) in the vaccine stimulate a person’s immune system to produce antibodies against the viruses. If the flu viruses invade a vaccinated person at a later time, the immune system recognizes the antigens and quickly responds to help destroy the viruses.
    About 5 to 10 percent of people who receive a flu vaccine experience mild, temporary side effects, typically soreness at the injection site. Young children who have not previously been exposed to the influenza virus are most likely to have side effects.
    Flu viruses constantly Change so different virus strains must be incorporated in vaccines from one year to the next. Scientists try to provide a good match between the vaccine and the most serious virus strains circulating at the time. But because it takes months to manufacture and distribute vaccines, decisions on their composition must be made well before the start of each flu season. Each February experts at the World Health Organization (WHO) recommend the composition of the vaccine for the forthcoming winter in the Northern Hemisphere; a second recommendation is made in September for vaccine to be used in the Southern Hemisphere. Typically vaccines contain antigens from three virus strains, usually two type A and one type B.
    According to the CDC, the success of the flu vaccines varies from one person to another. In healthy young adults, the vaccines are 70 to 90 percent effective in preventing the disease, In the elderly and people with certain chronic medical conditions, the vaccines are less effective in preventing illness but help reduce the severity of an infection and the risk of major complications or death. Studies show that flu vaccines reduce hospitalization by about 70 percent and death by about 85 percent among elderly people.
    Historic outbreaks
    Evidence suggests that all influenza viruses in mammals, including humans, derived from viruses in wild ducks and other birds. Some of these viruses could have been acquired by humans thousands of years ago. But medical historians know of no clearly identifiable influenza epidemics until large-scale outbreaks occurred in Europe in 1510, 1557, and 1580. The 1580 outbreak also spread into Africa and Asia, making it the first known pandemic (广大地域流行). Pandemics have occurred periodically ever since. Major pandemics took place in 17294 1730, 173241733, 1781 1782, 183041831, 1833, and 1889-1890. The last of these, called the Russian flu because it reached Europe from the east, was the first pandemic for which detailed records are available.
    In the 20th century, major pandemics occurred in 1918～1919, 1957～1958, and 1968～1969. The 1918～1919 pandemic was the most destructive in recorded history. It started as World War Ⅰ (1914～1918) was ending and caused 20 million deaths--twice as many deaths as the war itself. When and where the pandemic began is uncertain, but because Spain experienced the first major outbreak, the disease came to be called the Spanish flu. The virus was exceptionally deadly; many of the deaths were among young adults age 20 to 40, a group usually not severely affected by influenza.
    No additionally pandemics occurred during the 20th century, but public health experts expect that there will be more pandemics in coming years. While scientists do not yet know how to accurately predict flu outbreaks, they have established an international network to track and monitor outbreaks so that health officials can take immediate preventive measures to avoid pandemics. The international network, called FluNet, consists of about 110 influenza centers in more than 80 countries and several World Health Organization (WHO) centers, all linked electronically.
It is proved that influenza viruses come from the viruses in ______.
选项
答案Wild docks and other birds．
解析 本题询问流感病毒的来源。Historic outbreaks第一段第一句说到流感病毒来源于野鸭和其他鸟类。
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