1. You can answer based on your personal experience of seeing advertisements on trains or other forms of transportation. 2. You can also discuss the prevalence and impact of such advertising, such as its frequency, effectiveness, or how it affects your travel experience.

1. 你可以根據自己在火車或其他交通工具上看到廣告的個人經驗來回答。 2. 你也可以討論這種廣告的普遍性和影響，如其頻率、效果或者它如何影響你的旅行體驗。