Recovery was almost impossible.
He is unable to finish it in an hour.
It is impossible for us to cross that river.
He says he will come, which is quite impossible.
It was next to impossible to get a trained pilot.
Your idea is absolutely impossible.
It's not absolutely impossible to climb the mountain.
It is impossible for me to answer the question.
To live without air is impossible.
We never thought of it as impossible to carry out.