List the two traits of public goods and give an example of such a good

They're free and they are open to the public. Free software, anything public domain knowledge, clean air, water, or anything along the lines of that.

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.