3. Given in each question are 4 sentences labeled A, B, C and D. Arrange these sentences to form a logically coherent paragraph.
A. There were no border guards then, no custom officials.
B. We were bounded only by the Earth and the ocean and the sky.
C. For 99.9 percent of the time of our being, we were hunters, foragers and wanderers.
D. The frontier was everywhere.