摘要：
There is a public bike service in Hangzhou City which provides great convenience to the tourists from all over the world. One may rent a bike at any s 阅读全文
摘要：
Weibo is known as the Chinese version of Twitter. One user on Weibo may have many followers, and may follow many other users as well. Hence a social n 阅读全文
摘要：
One way that the police finds the head of a gang is to check people's phone calls. If there is a phone call between A and B, we say that A and B is re 阅读全文