5 . 下面5个单句各有1处语言错误。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：每处错误及其修改均仅限一词
1. It was three days ago when Tom was killed in a car accident.
2. Under the help of the computer, it is now easy to deal with and share information.
3. They helped each other in studies and as the result they made great progress and became good friends.
4. After he heard the bad news, his face took on a worrying expression.
5. A number of high buildings have arisen from where there was nothing a year ago but ruins.