The sullen customer refused to explain the problem and simply demanded a full refund.

那位悶悶不樂的顧客不肯說明問題，只一味要求全額退款。

After the budget cuts were announced, the team sat in sullen silence through the meeting.

預算刪減的消息宣布後，團隊在整場會議中都陰沉地沉默不語。

The delayed passengers grew sullen as the airline postponed their flight for the third time.

航空公司第三度延後班機，延誤的旅客們臉色越來越陰沉。