What regular service did The Associated Press and United Press International begin to offer subscribing newspapers in the 1930’s? A.A new system of weather forecasting. B.Twice daily weather maps. C.Cloud-cover photographs. D.An air-mass analysis.
Đáp án đúng: D Giải chi tiết:Câu thứ 3 trong bài chứa thông tin này : "In the 1930's, when interest in aviation and progress in air-mass analysis made weather patterns more news worthy, ..."