Answer:
If a man carries my burden they will get crushed to death. Though not rich I leave silver in my track.
I am wood that is neither hard straight or crooked
I keep growing and am practically indestructible. I get eaten, but always come back. I survive cold and lie everywhere. You see me everyday. What am I?
What is the edge of earth and bread?
I am taken from a mine and shut in a wooden case from which I am never released. Yet I am used by almost everybody. What am I?
I am your mother's brother's only brother in law. Who am I?