英文關鍵字
abstract
america
animation
background
barbed
barrier
bill
border
boundary
concept
cost
costly
country
crossing
customs
defense
enforcement
expense
expensive
fence
fund
funding
government
homeland
illegal
illustration
immigrant
immigration
impasse
mexican
mexico
migration
money
nation
national
politics
president
price
protect
protection
rendering
secure
security
states
symbol
united
usa
wall