I think bicycles might be the best means of tranport of Viet Nam because it use our engery to go, not using petrol or gas it can reduce pollution around the world.Also ride your bike is a way to protect the environment, you will be greener and greener and more! If You ride your bike usually for a long range, your carbon footprint can stay still small. Small fact: If you and familly go cycling everyday in 1 month it will reduce 99kg of carbon dioxe(CO2).These are my reason why bicycles are the best means of transport in Viet Nam.I hope people will goes byy bike more to save the enviroment from pollutions.