selective level meter

例句：

1. 1. The selective breedingprocess is used to improve the quality oflivestock.
   选择性育种过程用于提高家畜的质量。
2. 2. The teacher was very selective inchoosing his students.
   老师在选择学生时非常挑剔。
3. 3. The researcher found that the selectivepressures were having a significant impact onthe species' evolution.
   研究者发现，选择性压力对物种进化产生了显著影响。