Earthquakes Practice:time-travel graphs and seismorgraphs QUESTIONS
1.How long does it take for a primary wave to travel 200km?
2.How long does it take for a secondary wave to travel 200km?
3.How far does a secondary wave travel in 10mins?
4.How far does a primary wave travel in 10mins?
5.How much lag time between the two waves will there be at 4000km?​

answer; i believe its called ; checks   and balances;

answer; eliminate parking problems in cities, because a car took up only half as much space as a horse and buggy;

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.