''Inside the Earth'' Part 1

Most scientists believe that

the Earth is filled with layers

of rock one on top of another.

In the middle or center there is

maybe a ball or core of metal

which is mostly iron. In addition,

The deepest hole we have been able

to dig into our very solid Earth is more

than four miles deep. The hole which

would show us for sure what is the

very middle of the earth would have
to be about four thousand miles deep.