兄と妹のなぞなぞ遊び！

There is a certain rural town.
A pair of siblings are playing a riddle.

"Bread is bread, but what kind of bread can't you eat?"
"Protest against the matter!"
“Eh, direct negotiation!?”

Let's solve the riddle together. All 50 questions!

■ How to play
・Enter the answer to the given riddle and press "This is it!" to answer.
・For the above question, the correct answer is "frying pan". "Iron plate" is also correct. But "rotten bread" is edible, so it's a mistake. Try out the answers you come up with.
・If you answer correctly, look at your sister's diagonal answer and then move on to the next question.
・When you don't understand, please use hints.