positive-negative control

例句：

1. 1.The experiment was designed to test the effectiveness of positive and negative controls.
   这个实验旨在测试阳性和阴性控制的效果。
2. 2.In drug development, positive and negative controls are crucial for ensuring safety and efficacy.
   在药物开发中，阳性和阴性控制对于确保安全性和有效性至关重要。
3. 3. The study found that both positive and negative controls were effective in reducing pain levels.
   研究发现，阳性和阴性控制都能有效降低疼痛水平。