Answer:
I'm as simple as a circle worthless as a leader; but when I follow a group their strength increases tenfold. By myself I'm practically nothing.
What is so fragile that saying its name breaks it?
I am black and white. I have strings I have keys. I make sound without my lips. I make dough with no flour
The more you take of me the more you leave behind.
I have a straight back and sharp teeth to cut objects.
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.