There is little doubt, however, that desertification in most areas results primarily from human activities rather than natural
processes. The semiarid lands bordering the deserts exist in a delicate ecological balance and are limited in their potential
to adjust to increased environmental pressures. Expanding populations are subjecting the land to increasing pressures to provide them with food and fuel. In wet periods, the land may be able to respond to these stresses. During the dry periods that are
common phenomena alond the desert margins, though, the pressure on the land is often far in excess of its diminished
capacity, and desertification results.
in dry periods, border areas have difficulty
-adjusting to stresses created by settlement
-retaining their fertility after desertification
-providing water for irrigating crops
-attracting populations in search of food and fuel
답이 1번인데 어느 문장을보고 1번인지 알수있을까요...