这位船长是整艘船的最高指挥官。

The captain is the ___master of the entire ship.

他是象棋大师，已经赢得了多个国际比赛。

He is a ___master of chess, having won several international tournaments.

经过三个月的刻苦练习，她完全掌握了钢琴演奏技巧。

After three months of hard practice, she finally ___mastered piano playing.

请确保将母版文件保存在安全的地方。

Make sure to store the ___master file in a secure place.