defined variable

例句：

1. 1. The teacher defined the problem for us clearly.
   老师为我们清晰地定义了这个问题。
2. 2. The company has defined its mission statement.
   公司已经明确了其使命声明。
3. 3. The definition of a word is crucial to understanding its usage.
   一个词的定义对于理解它的用法至关重要。