4.
1. change.
2. departs from.
3. platform.
4. arrives.
5. to.
6. train.
7. advance.
5.
1. My last train journey was last summer.
2. We went to the sea, because it was nice, warm weather and we wanted to sunbath.
3. The fare was 100 rubles.
4. No, we didn't book it in advance, we bought it on the station.
5. It was a direct train, so we didn't need to change trains.