Answer:
Many immigrants moved to the United States in the late 1800s to help build the railroads.
Explanation:
Answer:
D
Explanation:
If NASA had constructed a Space Shuttle without knowing if it would be safe for its passengers, there could be many casualties. So they would test it beforehand using a model, to make sure that it will be safe and sturdy for when they build it.
Answer:
The answer is Divergent plate boundary.
Explanation:
Under the rising convection current of magma, the plates move apart from each other causing crack. The uprising magma would then fill the crack and cools down to form new plate material which adds to the lithosphere.
