Black holes are objects so dense that not even light can escape their gravity, and since nothing can travel faster than light, nothing can escape from inside a black hole.

• 黑洞是一种星体，密度非常之大，就连光也逃离不了它的重力吸引，既然没什么东西比光速更快，所以在黑洞中没有物质能从它里面逃逸出来。