Translation of retrete

Mr. Chang informed me that you have a customer that requires similar applications to what my customers have here in Switzerland. I am planning my next trip and I will consider visiting you too.
The climb was much exhausting than I had presumed. I had forgotten that we were at high altitude where there is less oxygen and that every step required double effort. It was a great exercise.
We went back and took our bags from the travel agent, where we left them earlier. We wanted to catch the bus back to the station before darkness, as we knew that people drove crazy over there.