要一篇英语的吸烟调查文。

The Flag of the World Health OrganizationThe World Health Organization (WHO) is a specialised United Nations agency which acts as a coordinator and researcher for public health around the world. Established on 7 April 1948, and headquartered in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health Organization, which had been an agency of the League of Nations. The WHO's constitution states that its mission "is the attainment by all peoples of the highest possible level of health." Its major task is to combat disease, especially key infectious diseases, and to promote the general health of the peoples of the world. Examples of its work include years of fighting smallpox. In 1979 the WHO declared that the disease had been eradicated - the first disease in history to be completely eliminated by deliberate human design. The WHO is nearing success in developing vaccines against malaria and schistosomiasis and aims to eradicate p