日韩色综合-日韩色中色-日韩色在线-日韩色哟哟-国产ts在线视频-国产suv精品一区二区69

手機(jī)APP下載

您現(xiàn)在的位置: 首頁 > 英語六級 > 六級真題 > 六級考試模擬試題 > 正文

2010年6月大學(xué)英語六級考試最后一套模擬題

來源:考試吧 編輯:Baul ?  可可英語APP下載 |  可可官方微信:ikekenet

  Part IV Reading Comprehension (Reading in Depth) (25 minutes)

  Section A

  Directions: In this section, there is a short passage with 5 questions or incomplete statements. Read the passage carefully. Then answer the questions or complete the statements in the fewest possible words on Answer Sheet 2.

  Questions 47 to 51 are based on the following passage.

  Wild ducks and other migratory(遷移的) birds could be important carriers of deadly bird flu, researchers say. Even so, the infectious-disease experts say there is no solid basis for killing wild birds to protect poultry and minimize the risk of human infection.

  The European team investigating the global spread of the H5N1 strain of avian influenza(禽流感)says certain duck species may be infecting wild bird populations. Geese and wading birds are also possible vectors(帶菌者)of the virus, the team says.

  The team's study was led by Björn Olsen of Umea University in Sweden. Olsen runs Europe's largest wild-bird flu monitoring program.

  Studies have shown that influenza viruses in lake water, generally passed via bird feces(糞), can stay infectious for up to 30 days. The migration or feeding behavior of dabbling ducks could at least partially explain the spread of the H5N1 strain of bird flu, the researchers add.

  This group of duck species includes mallards, teal, pintails, and others that feed at or near the surface, where viruses in water are most likely to be picked up. Perhaps as a result, dabblers have the highest known rates of avian influenza infection, the study says. For instance, nearly 13 percent of mallards tested positive for bird flu. Other species tested include the American black duck (18.1 percent), blue-winged teal (11.5 percent), and northern pintail (11.2 percent).

  However, bird flu viruses appear to exist in ducks in a low-pathogenic form, meaning infection doesn't usually lead to severe illness and death.

  "Dabbling ducks are for sure the prime hosts for low pathogenic viruses," said study co-author Ron Fouchier, a virologist at the Erasmus Medical Center in Rotterdam, Netherlands. "But the big question is, how much of our knowledge about these viruses can we translate to high-pathogenic viruses such as the H5N1 strain of bird flu?"

  In poultry avian viruses can mutate(變異)into more virulent influenza strains, including H5N1. If this mutated virus then finds its way back into wild populations, the birds could then spread the disease through migration.

  Some scientists have argued that wild birds infected with HN51 would be too ill to migrate. Swans, for instance, appear to be particularly vulnerable to the strain. "Swans apparently drop dead quite easily, but they are unlikely to be the vector because they are not going to fly very far if they are dead," Fouchier said.

  But the study team says that some birds that have been purposely infected for the sake of research show that wild birds can survive H5N1. "For some reason H5N1 has adapted so it no longer kills dabbling ducks," Fouchier said. This means the ducks may be able to spread the virus over a wide area.

  The study team says migratory geese may also be vectors, because they often graze in huge flocks, a practice that could encourage transmission.

  Migrating ducks, the researchers add, "could provide an intercontinental bridge" for bird flu to North America, which has not yet had any known cases of H5N1.

47. According to the author, what may be the possible carriers of bird flu?

  48. The main sources of influenza viruses in lake water are ________, which may stay infectious for up to 30 days.

  49. By saying "bird flu viruses appear to exist in ducks in a low-pathogenic form" (Para. 6), the author suggests that infection ________.

  50. On what condition can the birds spread the influenza through migration?

  51. According to the study team, ________ is a practice that can encourage transmission of the bird flu.

重點(diǎn)單詞   查看全部解釋    
mutate [mju:'teit, 'mju:-]

想一想再看

vi. 變化,產(chǎn)生突變 vt. 改變,使突變

聯(lián)想記憶
tendency ['tendənsi]

想一想再看

n. 趨勢,傾向

聯(lián)想記憶
primary ['praiməri]

想一想再看

adj. 主要的,初期的,根本的,初等教育的

聯(lián)想記憶
embarrassment [im'bærəsmənt]

想一想再看

n. 困窘,尷尬,困難

 
disguise [dis'gaiz]

想一想再看

n. 假面目,偽裝物,假裝
vt. 假裝,假扮

聯(lián)想記憶
memorial [mi'mɔ:riəl]

想一想再看

adj. 紀(jì)念的,追悼的
n. 紀(jì)念碑(堂),

 
naive [nɑ'i:v]

想一想再看

adj. 天真的,幼稚的

聯(lián)想記憶
credit ['kredit]

想一想再看

n. 信用,榮譽(yù),貸款,學(xué)分,贊揚(yáng),賒欠,貸方

聯(lián)想記憶
challenging ['tʃælindʒiŋ]

想一想再看

adj. 大膽的(復(fù)雜的,有前途的,挑戰(zhàn)的) n. 復(fù)雜

 
impossible [im'pɔsəbl]

想一想再看

adj. 不可能的,做不到的
adj.

聯(lián)想記憶
?
發(fā)布評論我來說2句

    最新文章

    可可英語官方微信(微信號:ikekenet)

    每天向大家推送短小精悍的英語學(xué)習(xí)資料.

    添加方式1.掃描上方可可官方微信二維碼。
    添加方式2.搜索微信號ikekenet添加即可。
    主站蜘蛛池模板: 自拍在线观看| 电影《忌讳》完整版| 电视剧《流金岁月》演员表| 香水有毒微电影无删减完整版 | 天下第一楼剧情介绍| 在人间在线观看完整版| 成年奶妈| 在路上 电影| 新娘大作战电影免费观看完整版| 电影儿媳| 千羽千翔公棚| 柯哀分析文| 老阿姨电影电视剧免费| 宅基地买卖合同协议书| 花有重开日电影| 24点数学题目100道| 女人香韩国电影| 胡凯莉| 好妻子剧情简介| 超越天堂菲律宾| 任喜宝| 大场久美子| 国家地理频道| 《西湖的绿》宗璞| 小小少年电影完整版在线观看| 补充电解质喝什么饮料| 梦醒长安| 教师政治学习笔记| 朱莉娅安| 秀人网周妍希| 囚禁空姐| 竹内纱里奈全部aⅴ在线看| leah| 无内裤全透明柔术视频| 内战电影免费观看2024年上映| 怀孕检查费用大概多少钱| 卖房子的女人的逆袭| 1998年槟榔西施| 抗日电影完整版| 潘霜霜惊艳写真照| 《求知报》答案|