What do ethnic groups have in common?

Ethnic group is that group of people who are known for having a common characteristic. Their common characteristic is only because of the culture or the inheritance that they have been through. Ethnicity is defines as the common cultural identity that the people of these group have.

it increase by 12% a year from 1812-1820

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.