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comes from the simple idea that a man entered a 'hole' to locate tunnels below ground.
The thinning of ozone layer. When this thinning reaches a certain concentration then it is ozone hole.
The twist drill uses flutes that act as an Archimedean screw to lift swarf from the hole.
Well that's a very simple answer.Earth can not become a Black Hole because we live on Earth as you know.
Its a hole in the ground,containing grave goods and a body.