master
v. /ˈmæs.tɚ/ B2
掌握；精通
To learn how to do something well.
仙境例句
The young Mock Turtle could never master Stretching, so he stayed short and round.
小时候的假海龟怎么也学不会“拉伸课”，所以一直又矮又圆。
原著这一句
The master was an old Turtle—we used to call him Tortoise—”
校长是一只老海龟——我们平时都管他叫先生——”
卡罗尔原著 · 第 9 章