题目内容：

短文改错

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。作文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏子符号（∧）并在其下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1.每处错误及其修改均仅限一词；

2.只允许修改10处，多者（从第11处起）不计分。

Facebook managed to put its vast treasure trove(宝藏) of user data to good use before Friday’s tragic terror attacks in Paris. The social network customized its safety check feature let users know whether their friends and loved ones in Paris are safe.

Users in the area are being alerted(通知) by Facebook’s mobile apps, asked them whether they are safe, and offering to check on any of their friends. The app has also been sending out alerts to anyone who has friends in Paris, and Facebook’s website lets anyone check on the status and whereabouts(去向) of their friends as well as.

Most people have seen Facebook’s safety check for the first time today, and the company actually lanched it in respond to the Nepal earthquake earlier this year. At the time, Facebook CEO Mark Zuckerberg wrote: “When disasters happen, people need to know their loved ones are safe. It’s moments like this when being able to connect really matters.”

Facebook wasn’t the only tech company to direct reach out to its users in Paris after the terror attacks. AirBnB（空中食宿） sent its customers in Paris a email advising them staying in place and follow the directions from local authorities, and Uber（优步） used its app to advise users “not to move if absolutely necessary.”