下面短文中共有10处错误，错误涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏词符号（∧），并在此符号下面写出该加的词。
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
Union is strength. Whenever you’re faced with difficulties, and cooperation plays an important part in getting you out of trouble.
There was a time that I was so proud that I overlooked my classmate, refusing to work together with them.Therefore, it was no doubt that I was left alone,suffering from loneliness and failure. Unluckily, a teacher impressed on me the value of cooperation.From then on, I learned to help others and turn to my friends for the help whenever I had difficulty finish a task on my own. Surely cooperation makes a great difference. Now I am getting on well with his friends.
My experience has teach me that only if we place great stress cooperation can we go beyond ourselves. As the saying go, “United we stand; divided we fall.”