Transportation crossword #1 (level 4)

Across

1. 1 You push with one foot to move. (7 letters)
2. 2 Train that runs under the city. (6 letters)
3. 3 Planes take off from there. (7 letters)
9. 9 It takes sick people to the hospital. (9 letters)
11. 11 Two wheels with an engine. (10 letters)
12. 12 Two wheels and pedals. (4 letters)
13. 13 Car you pay to ride in. (4 letters)
14. 14 It runs on rails. (5 letters)
15. 15 It runs on rails through the city. (4 letters)

Down

1. 1 Boat that travels underwater. (9 letters)
4. 4 Machine that pulls the plow. (7 letters)
5. 5 Cars drive on it. (4 letters)
6. 6 Hot air makes it fly. (7 letters)
7. 7 It flies with a big rotor. (10 letters)
8. 8 Shoes with wheels. (6 letters)
10. 10 It goes into space. (6 letters)