(1)The raising of livestock is a major economic activity in semiarid lands, where grasses are generally the dominant type of natural vegetation. (2) The consequences of an excessive number of livestock grazing in an area are the reduction of the vegeta¬tion cover and the trampling and pulverization of the soil. (3) This is usually followed by the drying of the soil and accelerated erosion. (4) Directions: Look at the part of the passage that is displayed above. The numbers (1), (2), (3), and (4) indicate where the following sentence could be added. This economic reliance on livestock in certain regions makes large tracts of land susceptible to overgrazing. Where would the sentence best fit?