听力原文： Hello, I was once a hostess. Now I am on my first bus trip and I'm quite surprised at the services offered during the trip. Included are meals on the way, rest rooms and public address announcements. Just now, I introduced myself to the hostess on the bus, and we told each other about experience on air and ground travel. At lunch time, she gave out menus offering a choice of sandwiches. As she started filling orders, she found that there weren't enough egg-salad sandwiches. She quickly went to whisper to the driver. The bus soon stopped. The hostess ran to another bum that was all the time following ours and she soon returned with a box of egg-salad sandwiches. As she passed my seat, she asked, 'Could you do that on a plane?' According to this passage, what kind of vehicle did the speaker always ride in the past?