the medical research council have now advised the government that the great increase in lung cancer is due mainly to smoking tobacco. it was closing time for checkpoint charlie which, for 29 years, has stood on the border as a mark of allied determination to defend the city. this is bbc world news, the latest headlines: the us and canada have both warned citizens of dangerous levels of heat as western north america faces an unprecedented heatwave. another body has been recovered from the rubble of a collapsed florida apartment building. that brings the number of confirmed dead to 11 with more than 150 people still missing. facebook�*s stock market