key range

例句：

1. 1. The key range of the experiment is to find out how effective it is.
   实验的关键范围是找出它的有效性如何。
2. 2.The key range of the data is within a certain range.
   数据的关键范围是在一定的范围内。
3. 3.The key range of the problem is to solve it quickly and efficiently.
   问题的关键范围是快速且有效地解决它。