Question

read the passage. then answer the question.
earth has an outer layer of rocks, or plates. these plates float on molten rock, which is in constant motion. first, the warmest material rises. then, it cools and sinks. finally, it warms and rises again.
its because of this motion that the plates move in different ways. they slide toward each other, away from each other, or across each other. however, all three movements are similar in that they can transform the landscape. mountains, volcanoes, and ocean trenches are formed from moving plates.
which signal word(s) tell you the structure of the passage?
first
then
its because of
are similar

Explanation:

Signal words like "First", "Then", and "Finally" are used to show a sequence of events or steps. These words help in understanding the chronological or procedural structure of the passage.

Answer:

First, Then