The major ingredient of magma is a. pahoehoe. b. silica. c. dissolved gases. d. obsidian.

D.

You can google it. the answer is d. international recognition

1. d: oceanic crust is thicker and contains a lot of granite2.d: where two continental plates are colliding  3.b.contour boundaries4.b.plates that are attracted to each other by gravity5.a.as two continental plates collide along a convergent boundary, mountains are formed.

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.