Sample：A letter on talking bus service in Beijing 英文书信(北京公共交通)
Dear Tony,
I am glad to know your grandpa is coming to Beijing.
Yes, your grandpa is right. The bus service in Beijing is really good now. there are more than 900 bus lines all over Beijing and bus can even take you to some small villages. Besides, special(yellow) seats are provided on buses. People do not have to spend a long time waiting for a bus and the tickets are very cheap.
I like taking a bus because I think it is comfortable and also good for our environment. So it is a good choice for your grandpa to travel by bus in Beijing.
If you have more questions, please ask me.
Yours,
Liu Jing