1. how are countries in the european union linked? check all that apply. a. they share a military. b. they have an official shared language. c. more share a common currency. d. they allow people to move easily between the countries. 2. why is it difficult to determine which countries belong to europe and which belong to southwest asia? a. the european union allows almost any country to join. b. most countries want to be associated with southwest asia. c. there is no natural physical boundary between europe and southwest asia.