显影剂

例句：

1. 1. The developer is the key ingredient in the process of developing photographic film.
   显影剂是摄影胶片处理过程中的关键成分。
2. 2. The chemical developer is used to fix the image on the film.
   化学显影剂用于在胶片上固定图像。
3. 3. The developer reacts with the dye to create a visible image.
   显影剂与染料反应，产生可见的图像。