Answer:
I am your mother's brother's only brother in law. Who am I?
What is as light as a feather, but not even the strongest man on earth can't hold it for more than 1 c)minute?
What is the word that even in plain sight remains hidden?
What goes up but never comes down?
The part of the bird, that is not in the sky, Which can swim in the ocean and always stay dry. What is it?
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.