2015年職稱英語考試衛(wèi)生類A級閱讀復(fù)習(xí)(7)

　　2015年職稱英語衛(wèi)生類A級閱讀復(fù)習(xí)

　　Life Expectancy in the Last Hundred Years

　　上世紀人類平均壽命的變化

　　A hundred years ago,life expectancy in developed countries was about 47: in the early 21st century, men in the United States and the United Kingdom can expect to live to about 74. Women to about 80, and these ages are rising all the time. What has brought about these changes? When we look at the life span of people l00 years ago, we need to look at the greatest killers of the time. In the early 20th century, these were the acute and often high infectious diseases such as smallpox. Many children died very young from these diseases and others, and the weak and elderly were always at risk.

　　n the developed world these diseases are far lessdeadly today, and in some cases have almost disappeared. A number of factor shave led to this: improvements in sanitation and hygiene, the discovery and use of antibiotics, which make bacterial diseases much less dangerous, and vaccinations against common diseases. In addition, people's general health has improved with improvements in our general environment: cleaner air, better means of preserving food,better and warmer housing，and better understanding of nutrition.

　　Genetically,we should all be able to live to about 85 but while people do live longer today, there are still some big killers around that are preventing US from consistently reaching that age. The problems that affect people today are the more chronic illnesses, such as heart disease and strokes, and those spread by viruses, such as influenza and AIDS l. Of course, cancer is a huge killer as well. In most cases these diseases affect older people, but there are worrying trends in the developed world with problems such as obesity leading to more heart disease and illnesses such as diabetes at younger ages.

　　The killers today can be classed as "lifestyle diseases",which means that it may be possible to halt their progress.

　　一百年前，發(fā)達國家的人口平均壽命約為47歲，到21世紀初，美英兩國男性平均壽命為74歲，女性約為80歲，人們的平均壽命一直在延長。是什么造成這樣的變化呢?在研究100年前人類的壽命時，我們需要注意當時的一些不治之癥。早在20世紀初期，這些不治之癥經(jīng)常是像天花之類的急性的高傳染病。許多兒童因此夭折(也有其他原因)，年邁體弱的人也總面臨著他們的威脅。

　　如今，這些疾病在發(fā)達國家已經(jīng)遠不能致命。這一變化歸于許多因素，比如：環(huán)境及個人衛(wèi)生的改善、抗生素的發(fā)現(xiàn)及使用(抗生素大大降低了細菌病的危險)以及常見疾病預(yù)防疫苗的接種。除此之外，更潔凈的空氣、更好的食物保鮮方法、更舒適溫暖的屋子還有對營養(yǎng)的進一步認識，這些總的環(huán)境的改善也促進了人們的整體健康。

　　從基因角度看，人都能活到85歲。但盡管現(xiàn)在人們壽命確實比以前長了，仍然有一些疾病使得我們不能都活到那個歲數(shù)?，F(xiàn)在困擾人們的是像心臟病、中風(fēng)那些更為慢性的疾病，還有像流行性感冒和艾滋病那些通過病毒傳染的疾病。當然，癌癥也是一大殺手。上述疾病大多影響著老年人，但令人擔憂的問題在發(fā)達國家日趨明顯，如：肥胖癥產(chǎn)生更多心臟病、糖尿病等其他疾病患者群漸成年輕化。

　　人們?nèi)绻堰@些疾病歸為“生活方式疾病”，這意味著人們生活方式的改善有可能阻止它們的進一步發(fā)展。