... characterized / 70 0 - foot - high dunes / giant sand mountains. a. The desert today is characterized with 70 0 - foot - high dunes but giant sand mountains. b. The desert today is characterized by 70 0 - ... Philby / in the 193 0s. a. The first white man traversed this desert was H. St.John Philby, in the 193 0s. b. The first white man traversed this desert and was H. St.John Philby, in the 193 0s. c. The ... around 90 0,000, and Mexicali, Baja California, Mexico, whose municipality also has a population of around 90 0,000. The municipality of Hermosillo, Sonora, Mexico has a population of around 70 0,000....