Several passengers grumbled about the long delay at the check-in counter this morning.

今天早上有幾位旅客對報到櫃檯的漫長延誤發牢騷。

Staff often grumble when managers schedule meetings late on Friday afternoons.

主管把會議排在週五傍晚時，員工常常抱怨連連。

The client grumbled that the shipment arrived two days later than promised.

客戶抱怨貨物比承諾的時間晚了兩天才送達。