长时间的阴雨天气使她的心情变得沉闷。

The prolonged rainy weather ___dulls her mood.

长时间盯着屏幕会使你的视力变得模糊。

Staring at the screen for too long ___dulls your vision.

长时间的重复工作磨灭了他的热情。

The repetitive work ___dulls his enthusiasm over time.