A witch that shows them mirror

They stumble upon a witch that shows them a mirror.

“This is a magic mirror” says the witch. “Tell it the truth, and you shall win fortunes. But if you dare to lie, you will vanish.”

The French goes first, and says: “I think my language is the most beautiful language in the world”. And he immediately vanishes.

The Italian guy says: “I think our food is the best tasting food in the world”. And he immediately vanishes.

The Chinese comes and says: “I think..” And he immediately vanishes.