Answer:usually a wall or a bridge seperates another country
Explanation: hope i helped
Obsidian is volcanic glass compared to other igneous rocks , there’s also no proper crystallization compared to the other igneous rocks
B. The continents on a map looked like they fit together.
A is the theory he proposed <em>after</em> making this observation
C and D would disprove his theory, not support it.
The primary case of Nigeria's water pollution would be oil spills.
