挑战书的英文：
kartell

He threw down the gauntlet and I accepted his challenge.
我接到了他的挑战书，并答应与他决斗。

It was an odd, florid challenge from someone who called himself "Muhammad the Prophet of God."
这是一个自称为“真主的使者穆罕默德”的人写来的一封奇特而绚丽的挑战书。