" We thought you were a cert! " said Fred, in a tone that suggested Harry had tricked them in some way.

“我还以为肯定是你呢！”弗雷德说，听他口气，好像哈利在某种程度上欺骗了他。

Put your money on Thorpe to win, he’s a dead cert.

【cert】你押索普获胜吧，他准会赢。