According to the passage, which of the following was an obstacle to the development of the icebox? A. Competition among the owners of refrigerated freight cars B. The lack of a network for th
According to the passage, which of the following was an obstacle to the development of the icebox?
A. Competition among the owners of refrigerated freight cars
B. The lack of a network for the distribution of ice
C. The use of insufficient insulation
D. Inadequate understanding of physics