|  
 UID978953 帖子393 积分565 学分1985 个 金币0 个 性别男 在线时间172 小时 
 | 
| some problems are difficult to solve, but there are lots of expressions that can help. for example, if we put two and two together,we might come up with the right answer. we know that two heads are better than one, it is always better to work with another person to solve problem . | 
 |