Letter A. The statement that best describes 21st-century migration flow to the United States is that l<span>arge numbers of immigrants and migrant workers, including skilled and unskilled laborers and many with advanced degrees, are coming to the United States from South and Central America.</span>
Answer:
A. The Asthenosphere is solid rock able to flow because of it's plasticity.
D. The Mesosphere is solid rock that remains rigid.
