单选题 In the 1950's, accumulating scientific evidence (26) cigarette smoking and lung cancer made a (27) impact (28) the smoking public. During this period many health agencies declared smoking to be a (29) hazard. US Surgeon GeneralLeroy E. Burney said in 1957, "The weight of the evidence is increasingly pointing to one direction: that (30) smoking is one of the causative factors in lung cancer." The initial reports had the heaviest impact, so (31) total cigarette production (32) in 1953 and again in 1954. (33) reports appeared to have less (34) on smoking habits, and by 1957 cigarette production had (35) above the 1952 level.
(36) four voluntary health organizations (37) president John F. Kennedy to (38) a commission to study the widespread implications of the tobacco problem, the Surgeon General' s Advisory Committee on Smoking and Health was (39) in 1962 to review and evaluate all (40) scientific data. When its report, Smoking and Health, was released in early 1964, cigarette (41) again declined (42) . Pipe and cigar smoking increased. More than 350 000 copies of the report were (43) and sold. (44) abstracts and pamphlets were prepared by the Public Health Service and other organizations (45) a massive educational campaign on the hazards of cigarette smoking.