Final answer:
The land bridge that humans used to cross over to North America is called Beringia. It connected northeast Siberia and what is now Alaska when sea levels were lower due to glacial ice formation on the continents.
Step-by-step explanation:
The land bridge that humans used to cross over to North America is called Beringia. Beringia was a section of low-lying land between modern Alaska and Russia that once served as a land bridge between continents. It connected northeast Siberia and what is now Alaska when sea levels were lower due to glacial ice formation on the continents.