Smoke is a mixture of gases，vaporized chemicals，minute particles of ash，and other solids.There is also nicotine4，which is a powerful poison，and black tar.As the smoke is breathed in，all these components from deposits on the membranes of the lungs.On the point of concentration is where the air tube，or bronchus，divides.Most lung cancer begins at this point.
注釋：
1.life expectancy壽命
2.cancer of bladder and the oral cavity膀胱癌和口腔癌
3.amputation of limbs截肢
4.nicotine尼古丁
譯文
吸煙與癌症
美國人每年抽煙六十億支(1970年)。這大約等於每個18歲以上的成年人一年要吸4195支煙。
人們進行了大量的科學研究以確定抽煙是有害健康的。證據顯示，吸煙一直對人體有嚴重的危害。許多研究小組的研究結果不容置疑地表明，吸食煙草，特別是吸卷煙與平均壽命縮短有關。
這一領域的研究人員大都相信吸煙是產生肺癌、喉癌的重要原因，膀胱癌、口腔癌也與它有關。吸煙還影響了心髒脈管和血管。現已查明吸煙與伯爾格氏病有關。這種疾病使手腳的細靜脈不斷縮小，從而引起劇烈疼痛甚至導致截肢。
吸煙產生的煙霧是一種混合氣體，包括氣化的化學物，極小的灰塵微粒及其他固體，還有毒性很強的尼古丁和黑焦油。當吸進煙霧時，所有這些物質都沉澱在肺膜上。在氣管和支氣管分支處有一個集中點，大部分肺癌的病因就在這裏。
(2)Coronary Heart Disease
冠心病
Heart and artery1 disease is also called No1 killer in the U.S.A.Nearly 790，000 people die each year of heart and artery diseases—— almost twice as many as die of cancer and about 15 times as many as are killed in automobile accidents.
Coronary heart disease is the most frequent and dangerous form of heart disease among adults，afflicting about a million.It causes about 65%of heart-disease deaths in persons between 45-64.It usually develops as a result of the buildup of cholesterol2 and other fatty substances3in the arteries that supply the heart with blood.
注釋：
1.artery動脈
2.cholesterol膽固醇
3.fatty substances脂肪性物質
譯文
冠心病
心髒病和動脈血管病又被稱為美國的“頭號殺手”。美國每年有近七十九萬人死於這兩種疾病，幾乎比死於癌症的人多一倍，大約是死於車禍的人的十五倍。