12. True or false: The U. S. has been a safe haven for many refugees, particularly in the nineteenth (1 point) and twentieth centuries.
O true
O false

Catac, dry land,and lizards

Answer (datum point);

Physical systems is the answer

The reason why i feel that the theory of plate tectonics is correct because scientists have found dinosaur bones of the same species in africa, asia, and in the americas. which means that they must have been together at one point in time. plate tectonics is also how the hawaiian islands were formed. as the plate hawaii is on was moving north west, magma would melt through the sea bottom and hardening. forming into the island chain. plate tectonics also explains the mariana trench. two plates were moving away from each other and made a giant crack in the ocean floor running 2,550 kilometers (1,500 miles)  long.