What is the best definition of the word naturalization

Select 3 oral histories from the section entitled, "oral histories of long walk events", and explain how you would feel if this experience happened to you.

The impeachment of president clinton by the u.s. house of representatives occurred with a. virtually all republicans supporting it, while virtually all democrats opposed it b. about two-thirds of republicans supporting it and about two-thirds of democrats opposing it c. half of all democrats and half of all republicans supporting it, while half of all democrats and half of all republicans opposed it d. virtually all democrats supporting it, while virtually all republicans opposed it

Why do many scientists suppose the land bridge theory of migration?