I think it might be B if not sorry
6 might be because it has the right definition?!?!
It is a measurement of a plane angle .
No light can escape from it. If the way we see things and colors is the light being absorbed and reflected, we cannot see a black hole if no light can be reflected. The only way scientists can tell if a black hole is present is the impact of it to the surrounding stars and gas.
The answer is for the winter concert
