Answer:either the first choice or the last choice
Explanation:
<span>Complex drainage systems to keep structures from flooding this works</span>
Answer:
the Native Americans attack's and injury and disease
Explanation:
those were the obstacles they experienced.
Mao's Red Guards started harassing Chinese intellectuals who supported capitalism
Mao's Red Guards ensured that all schools in China taught from Mao's Little Red Book.
Some push factors were the chance to get rich, Dry farming, owning land, escaping the nightmares of the south ( slaves ). There were also longhorns to sell. Some pull factors were relatives and spouses not wanting them to go.
