The manager warned that only a simpleton would sign a contract without reading it.

經理警告說，只有傻瓜才會不看合約就簽名。

Don't treat customers like simpletons; explain the refund policy clearly and respectfully.

別把顧客當傻瓜看待，請清楚且有禮貌地說明退款政策。

He felt like a simpleton after booking the flight for the wrong month.

他把機票訂錯月份後，覺得自己像個笨蛋。