Transport through time

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Across
  1. 2. to be protected from harm or injury
  2. 3. to guide something in the right direction
  3. 4. railway engines
  4. 5. the steady flow of water or air in one direction
Down
  1. 1. goods carried by sea, air or road
  2. 2. almost, but not exactly the same
  3. 5. waterways made by people that boars can travel on, for transporting people or goods
  4. 6. to train a wild animal to listen to instructions