People's incomes are limited because
a. they generally spend too much.
b. individual human capital is limited.
c. companies never pay people what they're worth.
d. they don't want to work more than 40 hours a week.

crop rotation kepy different plants in the soil instead of once constintly. when switching out plants you have different nutrients being absorbed at different speeds and different roots growing differently therfore the spoil and water flow have to adapt and carry fresh nutrients to carry the constant changes that were going on in the soil.

the adoption by russian princes of the mongols' diplomatic rituals

roosevelt, a progressive reformer, earned a reputation as a "trust buster" through his regulatory reforms and anti-trust prosecutions. his "square deal" included regulation of railroad rates and pure foods and drugs; he saw it as a fair deal for both the average citizen and the businessmen.