The inhalation (吸入) of asbestos particles is associated with a number of lung diseases, such as asbestosis and ___50___ cancer.
Asbestosis is caused by the entry of asbestos particles into the wall of the alveoli, causing scarring which limits the functioning of the lungs. The lung ___51___ its elasticity and may change shape. The initial symptoms of asbestosis are a tightness in the chest and breathlessness. In its ___52___ stages, sufferers develop the barrel-shaped chests associated with emphysema, cyanosis, (where the skin takes a bluish ___53___ ) and club fingers.
Lung cancer, the generic ___54___ for malignant tumors（肿瘤）of the alveoli and bronchial tubes, has been shown to be directly ___55___ to the inhalation of asbestos particles. As in the case of asbestosis, there is generally a period of inactiveness which may ___56___ from 25 to 30 years after initial exposure, despite the ___57___of further exposure. Research suggests that there is a direct correlation between the degree of exposure to asbestos ___58___the incidence of lung cancer. Where exposure occurs, the level of risk is further ___59___ by cigarette smoking. Asbestos workers who smoke cigarettes have a 90% greater risk of catching lung cancer than workers who do not ___60___.
Exposure to blue asbestos has been shown to producemesothelioma, a rare cancer of the outer lining of the lung or pleura. In a normal population the incidence of mesothelioma is extremely ___61___. Where epidemiological surveys have revealed a higher incidence of the disease, it is almost always related to ___62___ exposure.
___63___ changes in lung tissue caused by exposure to asbestos are pleural plaques and effusions. The former refer to a thickening of the lining of the chest wall, ___64___ the latter consists of a collection of fluid in the chest region outside the lungs. Pleural plaques commonly remain undiagnosed and generally have no detrimental effect on health.
| 小题1: | | A．skin | B．blood | C．liver | D．lung |
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| 小题2: | | A．loses | B．gains | C．improves | D．tightens |
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| 小题3: | | A．early | B．formal | C．later | D．final |
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| 小题4: | | A．size | B．color | C．sound | D．smell |
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| 小题5: | | A．noun | B．term | C．way | D．approach |
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| 小题6: | | A．related | B．revealed | C．compared | D．exposed |
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| 小题7: | | A．disappear | B．spread | C．live | D．extend |
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| 小题8: | | A．presence | B．activeness | C．absence | D．intensity |
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| 小题9: | | A．and | B．alongside | C．as well as | D．plus |
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| 小题10: | | A．decreased | B．lost | C．doubled | D．increased |
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| 小题11: | | A．diet | B．drink | C．smoke | D．fare |
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| 小题12: | | A．high | B．low | C．common | D．frequent |
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| 小题13: | | A．lead | B．asbestos | C．carbon | D．hydrogen |
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| 小题14: | | A．Three | B．Some | C．No | D．Other |
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| 小题15: | | A．in case | B．now that | C．whereas | D．unless |
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