北京市普通中学高中英语 Unit 21 Human Biology lesson 3教学学案（无答案） 北师大版选修7.doc

unit 21 human biology epidemics throughout historywith recent news reports connected bird flu with a killer epidemic in the past , jim smith looks through the history of epidemics for clues about what the future might hold. bacteria and viruses have been around since the beginning of life on earth and many of todays diseases have existed as long as humans have. it is important to look at the spread of diseases throughout history to discover the causes and effects of epidemics , and hopefully , foresee and prevent them in the future, especially as scientists proved that bird flu is a modern adaptation of the same virus of the spanish flu. one of the earliest epidemics on record happened about 500-550 ad when the roman emperor at the time was attempting to rebuild the roman empire . this epidemic ， which was called justinians plague , swept through north africa , the middle east and europe. scientists now guess that up to 50% of the areas population died from this epidemic making it one of the main causes of the fall of the roman empire. in the 1330s , the epidemic returned , this time in asia . this spread rapidly and became known as “the black death ” as one symptom was black spots on the body . in urban areas all over europe , asia , africa and the middle east , up to one half of the population was lost to the black death . another epidemic that spread in similar conditions was the spanish flu. it struck about 1918-1920 and left families mourning worldwide. having killed up to 50 million people in 18 months , with a tendency to strike the young and fit rather than the old . more people died of the flu than died in the war . yet , somehow , it was forgotten by history until very recently when sars became a cause for concern . the sars epidemic began in 2002 with a lung disease in guangdong province and spread quickly after dr liu jianjun, the carrier , came to hong kong and passed the virus to people who carried it to canada , vietnam and singapore. over nine months , 8000 cases were reported in over 30 countries across five different continents and 774 people died . although these statistics are much less impressive than those for the spanish flu , sars was still very alarming for a few key reasons. generally, sars symptoms include a high fever, body aches, and headaches.however, as the illness progresses, most patients eventually develop pneumonia.the sars virus spreads mainly by close human contact, either through the air or surface-touching.no one really knew much about sars as it was completely new. this meant that there were no prescription drugs or tablets to treat it and doctors were not sure how to prevent it either.since most people had no natural defences against the disease, it was also harmful to the doctors and nurses treating sars patients. since the sars epidemic ended , scientists have been doing trials on treatments to prohibit any future outbreaks . modern communication technology and medical research techniques allow health experts all over the world to unite , share knowledge , and work together without pause to help put sars behind us. meanwhile , governments worldwide have also underlined the fact that thorough and systematic medical research on bird flu needs to lead to a cure as soon as possible . countries will need to work together to do this as the sars epidemic proved how teamwork among nations can save lives. with all the international effort being made, we have to have faith that there will be solutions in time to stop a bird flu epidemic in its tracks. word bank acute (adj.) -severe (严重的), sharp （剧烈的）adaptation (n.)-changecancer (n.)-a kind of disease which can always cause deathcarrier(n.) -person or animal that can transmit(传染) a disease to others .epidemic(n.) -disease spreading quickly among many people in the same place for a time, eg. bird flu , sarsempire (n.)-countries under a single ruler or ruling power . eg. the roman empireforesee (v.)-predictfaith(n.) -confidencemourn(v.) -feel or show sorrow or regret for the loss of sb/sthprohibit(v.) -forbid(禁止) sth or sb from doing sth esp by laws , rules or regulations. eg. smoking is prohibited.pause(v./n.) -temporary (暂时的) stop in action or speech.press(n.) - the news sections of media prescription(n.) - doctors write instruction(说明) for the use of a medicine.rebuild(v.)-build it againroutine(n.) - regular rule ; statistics (n.)-collection of information show in numberssymptom (n.)-change in the body that indicates （表明）an illnesssystematic (adj.) -done or acting according to a system or plan.trial (n.) -experiment, test.tissue(n.) -mass of cells forming the body of an animal or plant.tablet(n.) -pill(药片)thorough (adj.)-done completely and with great attention to detail.teamwork(n.)-work together urban(adj.) -situated in or living in a city unite(adj.)-come or join togetherunderline(v.)-draw a line under a word or sentence.wipe out(v.)-destroyed completely reading task 2: try to put the words into proper part according to the textpart 1: name、 time 、 cause part 2:part 3:part 4:part 5: reading task 1: read para 5-9 and fill the chart with the detail informationpart1: introduction the sars epidemic began in_. with _in guangdong provincepart 2: _were reported in over _ countries across _ different continents and _ people died . part 3:1.generally, sars _ include a high fever, _, and _.however, as the illness progresses, most patients eventually _ pneumonia . 2.the sars virus _ mainly by close _, either through the air or_.part 4: there were no _ _ or _ to treat it and doctors were not sure how to _ it either. since most people had no natural _ against the disease, it was also _ to the doctors and nurses treating sars patients.part 5:summary1. scientists have been doing _ on treatments to _ any future outbreaks . 2. 2.modern _ technology and _ research techniques allow health experts all over the world to _ , _ knowledge , and _ together without _ to help put sars behind us. ebola_the file of an epidemicepidemic: ebola measure:1. the world health organisation appealed （呼吁）all the other counties to give necessary medical aids to west african government .2.the chinese medical team arrived in africa in september, 2014 to provide medical care to local patients and fight the virus together.time: fe