用户可以自由买卖商品,注册的用户还可以进行留言，其他用户可以进行评论-the user can buy or sail goods，and the user who has registed can give a message which other people can be commented

学习文件，有助于学习，学习天天向上。学如逆水行舟，不进则退。- ON划词翻译ON实时翻译 Learning file, contribute to learning, learning and make progress every day. Learning is like sail against the current, either