Translation of "확실하지" in English

알다시피, 선택성이 있는 건 확실하지 않아요

You know, there's no sure things with electability.

15m가 넘을지 안 넘을지 확실하지 않습니다 어떻게 생각하세요?

I'm not sure whether that's further than 50 ft. or not. What do you think?

문제는 돌출부가 많다는 겁니다 그리고 암벽의 상태도 확실하지 않고요

What's difficult is a lot of this is overhanging. And I'm just not sure how good the rock is.