How to prevent children from getting hurt while riding bicycles?

Children bicycle chain cover is indispensable, saddle the highest height is equal to or greater than 560 mm of children bicycle should be put in a plate of chain cover or other protective device in order to cover the outer surface of the chain and sprocket meshing, when all mesh on the sprocket chain, plate chain cover should be in diameter direction beyond the outer side of the chain, other protective device instead of plate chain cover, is covered live should be extended to the scope of initial into the chain sprocket pieces on both sides of the point along the chain to at least 25 mm. A child's bicycle with the highest saddle height below 560mm should be equipped with a chain cover that covers the outer surface and edges of the chain, sprocket and flywheel, as well as the inner surface of the chain and sprocket meshing to prevent the child from getting his fingers into it and getting hurt. Since children's bicycles are not used for road riding, they must be used under the supervision of adults and must not be used on roads.