Which of these units would be used to estimate the density of a tennis
ball?
a) g/mm3
b) g/cm3
c) kg/cm3
d) kg/m3

answer: b

explanation:

a tennis ball is about 50 grams so using kg would result in a decimal which we don't really want.

also, a tennis ball is pretty big (about 8cm^3) so using mm^3 wouldn't make too much sense since it would result in a big number (8000 mm^3).

so g/cm^3 would make the most sense.

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