星期五, 12月 23, 2005

新聞看科學》去年禽流感考題 占了14分

一般人感冒,了不起吃藥、打針,很快就痊癒,死亡率很低。但H5N1禽流感的致命率卻高達五成以上,關鍵何在?這是去年大學指考自然科的題目。 P> 去年東南亞禽流感肆虐,大學指考的英文、自然科各出了一道題組,共占14分,今年禽流感疫情更加嚴重,明年元月的學測及7月指考,禽流感很可能再次入題。
去年指考自然科考了一組禽流感閱讀題,主要考A型流感病毒H、N蛋白的功用,前者是病毒進入細胞之鑰,後者是病毒增殖後,破細胞而出的關鍵。
去年還要考生透過兩種蛋白的組合,辨別何種是A型流感,考生只要知道H有15種(目前已增為16種)、N有9種,凡病毒名稱在H1-H15及N1-N9之間的病毒,都是A型流感病毒。
另外,去年還考「人體免疫細胞對禽流感病毒的過度反應,才是禽流感致命的關鍵」,為什麼?
台大醫院感染科主任張上淳說,一般流感病毒入侵人體後,體內免疫系統會馬上拉警報,派出吞噬細胞(白血球)吃掉病毒;被感染細胞也會分泌激素壓制病毒活性,有時不吃藥也能痊癒。
但研究發現,H5N1和SARS病毒類似,入侵人體後,可能引發過度免疫反應,殺傷正常細胞,產生血管壁破裂、血水滲入肺部的發炎症狀,最後呼吸衰竭而死。
張上淳說,H5N1為何造成過度免疫反應,至今原因不明;為何感染病毒後,有人很快致命,但也有人沒事,同樣是個謎。
去年大學指考英文科禽流感閱讀題(單選)
Avian influenza, or "bird flu," is a contagious diseasecaused by viruses that normally infect only birds and, lesscommonly, pigs. __26__ all bird species are thought to besusceptible to infection, domestic poultry flocks areespecially vulnerable to infections that can rapidly reachepidemic proportions. Outbreaks of avian influenza __27__ be devastating for thepoultry industry and for farmers. For example, an outbreakof avian influenza in the USA in 1983-1984 resulted in thedestruction of more than 17 million birds __28__ nearly US$65 million. Economic consequences are often most serious indeveloping countries __29__ poultry raising is an importantsource of income, and of food, for impoverished ruralfarmers and their families. When outbreaks become widespreadwithin a country, control can be extremely difficult.__30__, government authorities usually undertake aggressiveemergency control measures as soon as an outbreak isdetected.
26. (A) Not (B) While (C) Since (D) Unless
27. (A) can (B) shall (C) dare (D) need
28. (A) with a view to (B) in regard to (C) at a cost of(D) on account of
29. (A) that (B) until (C) although (D) where30. (A) Instead (B) Therefore (C) By no means (D) On thecontrary
26-30題答案:B、A、C、D、B 資料來源/大考中心 【2005/12/23 聯合報】

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