This is the largest reservoir of fresh water on earth and contains about 75% of the fresh water on earth. this water feature covers about 10% of the land on earth. a) frozen b) ocean c) rivers d) wetlands

The changes to agriculture in the united states since 1900 is that increased mechanization has increased food production, thereby increasing the need for labor. there has been an increased need for higher speeds of food production due the fact that the population in the united states continues to rise.