Answer: D) Companies replaced hand-operated brakes with air brakes on trains.
The correct answer choice is "A". Half of refugees that came to the US in 2007 were from Africa and Asia.
Answer:
Leif Erikson
Explanation:
Vinland, Vineland or Winland (Old Norse: Vínland) is the area of coastal North America explored by Norse Vikings, where Leif Erikson first landed around AD 1000, approximately five centuries prior to the voyages of Christopher Columbus and John Cabot.