What Am I Riddles

Question: There are two sisters: one gives birth to the other and she, in turn, gives birth to the first. Who are the two sisters?

Question: You throw away the outside, eat the inside, and throw away the inside.

Question: Filled with garb,
the price is free.
Just return what you don't need.

What am I?

Question: I have lakes with no fish.
I have roads with no cars.

What am I?

Question: Thirty men and only two women, but they hold the most power.
Dressed in black and white, they could fight for hours.

Who are they?