What is the central idea of the text? What is black whole

A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying.

Because no light can get out, people can't see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.

Explanation:

Hope that helps!

the answer is emerged from.

orpheus descended to hades, the world of the death to rescue eurydice. no mortal had ever done this before him, he survived because he was protected by the gods. the word "underworld" gives us a clue, he emerged from it like a whale emerges form sea for exemple.

right angles are formed by perpendicular lines. if the lines would extend, to make two intersecting lines, they would form four right angles.