Backfilling is the right one
If you could dig a tunnel right through the Earth you could theoretically free-fall to the centre of our planet in just eighteen minutes. You can’t, of course: such a tunnel would have to tolerate temperatures as high as the surface of the Sun and pressures three and a half million times greater than those at the Earth’s surface.
They give us informations about our ancestors and how did they live and what did they do and than compare it to present way's of life.
<span>Good Morning!
The atmospheric layer closest to us is the troposphere.
Hugs!</span>
