Answer:
What is the edge of earth and bread?
What has one head one foot and four legs?
I begin your sentences.
I walk on 4 legs in the morning 2 legs at noon and 3 legs at night.
You use a knife to slice my head and weep beside me when I am dead.
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.