To change gross income, someone would need to

I believe the answer is: Earn more money

Gross income refers to the amount of money that you received from your job before it is deducted for job related expense, taxes and insurance. The amount of gross income would be increased as you earn more money from your salary or business profit.

classical republicanism, also known as civic humanism, is a form of republicanism  developed in the renaissance inspired by the governmental forms and writings of  classical  antiquity, especially such  classical  writers as aristotle, polybius, and cicero.

the correct answer is the following is a list of inventions made in the medieval islamic world, especially during the "islamic golden age" (8th to 13th centuries),[1][2] as well as the late medieval period, especially in the emirate of granada and the ottoman empire.

science and technology in the islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including persia, india, china, and greece-roman antiquity, while making a number of improvements and innovations.