The causes of air pollution (human activities and natural reasons)

These are largely the result of human reliance on fossil fuels and heavy industry, but can also be due to the accumulation of waste, modern agriculture, and other man-made processes. The combustion of fossil fuels like coal, petroleum and other factory combustibles is a major cause of air pollution

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them  

hey there!

mass = 6.75 g

volume =   9 cm³

therefore:

d = mass / volume

d   = 6.75 / 9

d = 0.7 g/cm³

answer b