Answer:
B
Explanation: because it means migration
Answer:
The answer should be: Companies replaced hand-operated brakes with air brakes on trains.
Explanation:
You have to think how hard it was for trains to stop with hand operated brakes. Trains go fast, and not stopping in time can be dangerous. Hope this helped :)
Answer:
I don't know exactly what you mean but i would say i conservative.
Explanation:
He is best known for d<span>iscovering North America</span>
