题目内容：

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。

I needed to start work on 11 o’clock that morning. As a usual, I went back to my office at about 10:30. The mall was almost empty at this time. While walked down the aisle, I suddenly heard the sound of a car engine. It was strangely because no vehicles were allowed enter the mall. The car stopped just outside a jewellery shop and out jump a few masked men, all armed with weapons. I did not hesitate and called the police using my mobile phone. Before that, I just stood aside while watching the robbers finish his job. The police came just in time outside the mall. There was a crash when the robber escaped.

Unfortunately, they were all arrested by the police.