请在这个框里签上您的名字。

Please put your ___signature in this box.

我原以为这是个玩笑，但当我看到签名时，我知道这是真的了。

I thought it was a joke but when I saw the ___signature, I knew it was for real.

没有正式签名，这份文件是无效的。

The document is not valid without an official ___signature.