define the file table

例句：

1. 1. The teacher defined the problem for us.
   老师给我们解释了这个问题。
2. 2. He defined his position clearly.
   他清楚地界定了自己的立场。
3. 3. The definition of a word is crucial in understanding its meaning.
   一个词的定义对于理解它的意思至关重要。