When geologists want to study an active earthquake fault, they often rely on a trenching study. ... They brace the walls, if needed, to prevent cave-ins, then they climb down into the trench and carefully map its walls, looking for signs of past earthquakes and ground movement.
The African continent isn't suffering from the environmental challenge "reforestation", since most of the continent hasn't suffered deforestation.
C. Nuclear to be honest, I don’t know, but I think this is the answer.
Answer:
Migration
Explanation:
They might want to migrate for greener pastures where opportunity are vast and the need of learning new language is important.
