He was back on familiar ground, dealing with the customers.

　　他又干起了與顧客打交道的老本行。

　　She looked around for a familiar face.

　　她環顧四周想尋找一個熟人。

　　Complaints about poor food in schools have become a familiar refrain.

　　抱怨學校飯菜差已是耳熟能詳的老調了。

　　The story had a familiar ring to it.

　　這個故事聽起來耳熟。

　　He became familiar with the dark underbelly of life in the city.

　　他逐漸熟悉都市生活的陰暗面。