How foolish I am to entertain doubts.

　　我心存疑慮是多么愚蠢啊。

　　It would be foolish to raise hopes unnecessarily.

　　無緣無故地寄托希望是愚蠢的。

　　You made me look a complete fool!

　　你弄得我像個十足的個傻瓜！

　　Art dealers fool a lot of people.

　　藝術品經銷商會愚弄許多人。