The CEO gave a solemn speech about cost control, ignoring every joke from the staff.

執行長一本正經地發表關於成本控制的演說，完全不理會員工的玩笑。

Our manager wore a solemn expression while explaining the new expense report rules.

我們經理一臉嚴肅地解說新的費用報告規定。

The airline representative solemnly insisted the delay was entirely the passengers' fault.

航空公司代表一本正經地堅稱，延誤完全是乘客的錯。