The manager was dubious about the supplier's promise to deliver all orders by Friday.

經理對供應商承諾週五前交齊所有訂單感到懷疑。

Several investors remain dubious that the startup can turn a profit next year.

幾位投資人仍懷疑這家新創公司明年能否轉虧為盈。

The customer sounded dubious when the agent said the refund would arrive tomorrow.

客服人員說退款明天就會入帳時,客戶聽起來半信半疑。