Adependent sometimes may claim a personal exemption on his or her own return.
a. true
b. false

This statement is false.
A dependent cannot claim a personal exemption on his or her own return. However, what a dependent can do is claim a limited standard deduction, which may or may not be granted. 

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.