题目内容：

根据短文内容及所给提示，在文中的空白处填写一个正确的单词。

Just now I 1. (check) my smartphone and found there was a short m2. from my friend, Liu Liang. He thanked me 3. my help. His computer was broken and was 4. (repair) by me yesterday. I think it is our duty to help friends when they meet 5. (difficult)．