What was the earliest known civilization?
a.
mesopotamia
b.
egypt
c.
sumer
d.
civitas

What led to the environmental damage that caused the dust bowl? 1. desert winds emerging from the southwest 2. rotating crops every year and having fallow land 3.overplanting throughout the great plains 4.a year-long drought

Where did people have to work with great organization to be successful at farming? a. on the yellow river basin c. on the hangzhou bay b. on the yangzi river basin d. on the hubei basin

What mountains did the first transcontinental railroad cross