Decide which one is the topic sentence of the paragraph? A、In time, this melted part rises as a magma. B、The formation of a volcanic eruption is a dramatic series of events. C、As the plate sinks, friction and the earth’s heat cause part of it to melt. D、The magma produces ...
aRifts contain fractures that serve as passageways for magma originating in the mantle. Rift zones account for most of the places where lava flows onto Earth’s surface. Fissure eruptions often occur along rift zones. These eruptions form lava that cools and solidifies into basalt, the most ...