【单选题】

　Noting that “an air route without markings（标记） is like a highway without signs,” Phoebe F. Omlie of the National Advisory（顾问） Committee for Aeronautics（航空家） in 1935 conceived（构思） a plan to paint town names and directional indicators on the roofs of buildings throughout the United States.

At Eleanor Roosevelt’s suggestion, the Bureau of Air commerce hired women fliers, among them Louise Thaden and Blanche Noyes, to scout（侦察） sites and get permission for the markers from local officials and building owners. Workers then painted the signs in orange characters, seven to twelve feet high and legible（可以看得出） from 3,000 feet. The system soon became the answer to a lost pilot’s prayer with 16,000 markers-one every 15 miles on every air route in the country.
29. What is the best title for this passage?
A.Eleanor Roosevelt’s Political Career.
B.Road Markers of the skies
C.How to Mark Signs
D.Women and Flying
30. Where would a marker most likely be found?
A.In an open field
B.In a grove of orange trees
C.On top of a building
D.On a major highway
31. Which of the following words would probably NOT appear on one of the markers described in the passage?
A.North
B.Louisville
C.Parking
D.Southeast
32. Who gave permission for the markers to be painted?
A.Louise Thaden
B.Eleanor Roosevelt
C.Local officials
D.Local pilots