Because of this, it is still uncertain who invented TV. (lines 6-7)

It was my first chance to use that software to edit the video extracts. I was uncertain about how to add background music to it. Don’t take his words seriously. He is a person of uncertain temper. The light is uncertain

未确定的

易变的

忽明忽暗的

I am uncertain what job I am going to take in the future.

我不确定将来我要做什么工作。