Ответ: 1. I use (название транспорта которым вы пользуетесь чаще всего) most of all.
2. Если вы когда-то ездили на поезде:
Yes, I've traveled by train. I really like it.
Если никогда не ездили, то:
No, I've never travelled by train. But I would like to. I heard it is very interesting.
3. Actually, I feel safe when I use public transport. But there is no doubt that it can also be dangerous. No one knows when it can be an accident.
4. Every day happens many accidents. Sometimes it is a car accident, sometimes it is a train, or plain. Even it can be a bicycle. So, every transport can be dangerous.
5. According to the answer of question 4, I can only say that every transport can be dangerous if we or someone else will use it wrong.
Объяснение: В основном, в этих вопросах нужно собственное мнение. Постаралась как могла.