Sample writings:

Writing 1:

I am a person who likes traveling around everywhere, and the modern transportation system provides convenience to me. For me, the most important transportation is subway because it is fast and stable, and it can help me get to my destination in time. Surely, in the beautiful days, I prefer to go out by bike or by foot when I visit my friends or go to the park. In all, the convenience of the modern transportation makes my life easier and I really enjoy it.

Writing 2:

Air travel has two advantages over train travel. First, it can save much time. We can fly from Beijing to Guangzhou just in two hours, but by train, we have to spend 20 hours or more. Second, air travel is more comfortable, because the plane flies so smoothly that we can rest well during the trip, while the train is crowded sometimes and passengers have to sit for a long time, which makes them tired. 
However, train travel also has its advantages. It’s very cheap. For example, it takes just several hundred yuan from Beijing to Guangzhou, while the price for a plane ticket is over one thousand yuan. Besides this, outside of the train's windows, we can enjoy the views of many big cities, such as Zhengzhou, Wuhan, and Changsha. So I think different people like different ways of traveling.

Writing 3:

Nowadays students can go to school by bus, by bike, on foot or by their parents' cars.
Going to school by car is a fast way, but it costs too much, we have to spend a lot of money on the car’s maintenance as well as purchasing it. Besides, too many cars on the road would cause traffic jams, and they also pollute the air.
Taking a bus is a good way. It is fast and cost less. It’s environmentally friendly compared to cars, but it still needs, and produces waste gases.
Riding to school is convenient way. It causes no pollution. But it is slower than a bus or a car.
Going on foot is the cheapest way of the all. It needs nothing but our own feet. It is the most environmentally friendly way. But it’s also the slowest way.