单项选择题
A. become very popular B. stopped being popular C. reached its lowest level in popularity D. stopped increasing in popularity
A.About 70%. B.Nearly 60%. C.Almost 50%. D.More than 12%.
A.research showed their health benefits B.people got the message from magazine covers and postage stamps C.scientific evidence of health benefits was shown on TV ads D.an increasing number of races were held in American cities