增加： 在缺词处加一个漏字符号（ ∧ ），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）不记分。
Last Friday, I was standing near a subway exit, tried to call a taxi. But no luck. Then I thought of the taxi-booking app my friend has recommended and I booked a taxi through my cell phone. Soon it came, and I stepped in, feeling pretty proudly of my high-tech way and satisfied with the convenience brought by the app. So later, I was upset to find that the driver was busy looking his cell phone to get the next order. It was just then when I began to worry about my safety. What's bad, the driver's informations might be unreliable. How can we passengers' legal rights be protecting if something bad happens? So be careful when you use the taxi-booking app the next time.
