根据汉语意思完成句子，每空一词。 

1. 迈克是他们班最聪明的学生之一。    

Mike is one of _____ _____ _____ in their class.

2. 孩子们正在户外举行晚会。  

The children are having a party _____ _____ _____ _____.

3. 我们现在没有时间可浪费。    

We have no time _____ _____ now.

4. 我经常帮助儿子学英语。    

I often help my son _____ _____ English.

5. 我觉得很难解释这些学生打架的原因。    

I found it _____ _____ _____ why the students fought with each other.

6. 照顾好老人是我们的职责。  

_____ _____ our duty_____ _____ _____ _____ the old.