How did people most likely arrive in northern europe

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.  

this is not a question its simply asking you to read and write a few sentences and   the question on the bottom its fairly easy, you can do this!