This is actually not a time "period," but it makes up the majority (approximately 4 billion years) of Earth's history. Major events occurring during this time include the early formation of Earth's oceans and the first appearance of life on Earth.

Which of the following statements best characterizes changes to agriculture in the united states since 1900? a. increased mechanization has reduced the need for labor.b. increased mechanization has increased the need for water, thereby increasing the need for labor.increased mechanization has increased the use of land, thereby increasing the need for labor.d. increased mechanization has increased food production, thereby increasing the need for labor. select the best answer from the choices provided.