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(wú)緣無(wú)故地寄托希望是愚蠢的。

　　You made me look a complete fool!

　　你弄得我像個(gè)十足的個(gè)傻瓜！

　　Art dealers fool a lot of people.

　　藝術(shù)品經(jīng)銷(xiāo)商會(huì )愚弄許多人。