scientists/ proved/ there/ close link/ smoking/ lung diseases/ such as/ cough/ tuberculosis/ and/ worst/ all/ fatal cancer.
A.Scientists have proved that there is a close link between smoking and lung diseases, such as cough and tuberculosis and the worst of all is fatal cancer.
B. Scientists have proved that there has been a close link of smoking with lung diseases, such as cough and tuberculosis and the worst of all, fatal cancer.
C.Scientists proved that there has been a close link from smoking to lung diseases, such as from cough to tuberculosis and worst of all, fatal cancer.
D.Scientists have been proving that there is a close link between smoking and lung diseases, such as cough and tuberculosis and worst of all is fatal cancer.