One possible version:
I’m writing to tell you more about the new form of sharing bike mobike mentioned in your latest letter.
It’s very convenient to use if you have a smart phone. What you do is find a nearest mobike through the APP, scan the QR code on the bike, and enjoy your trip. Compared to other forms of sharing bike, the greatest advantage of mobike is that you can easily find one and never worry about where to park it. It is becoming a new trend as a means of transportation, which relieves the traffic pressure and does good to the environment as well.
Hope to ride a mobike with you in China.
Welcome to Hangzhou. I am Li Yue, president of the Student Union in my school. I'd like to briefly introduce the Hangzhou Public Bicycle Service to you. Our city insists to protect the environment, so we began to use the Public Bicycle Service to reduce the traffic stress in 2008. There were 65 thousand bicycles for people to use in daily life. In general, more than 8 million people have to use them every year.
Some people think they are very useful and believe they will make our society more beautiful. Others think they are not convenient enough. As far as I can see, reading a bicycle is so interesting. We can take exercise with it. Meanwhile, Our environment get protected. Let's go into action!