Answer:
What gets sharper the more you use it?
I am an instrument that you can hear but cannot see or touch. What am I?
I am found in the sea and on land but I do not walk or swim. I travel by foot but I am toeless. No matter where I go, I am never far from home. What am I?
I produce wool and spit a lot
The shorter I am the bigger I am.
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.