老师傅正在指导学徒。

The ___master is instructing his apprentice.

经过多年的训练，他终于成为了这项技术的掌控者。

After years of training, he finally became the ___master of this technique.

她花了三个月时间才完全掌握了这门语言。

It took her three months to ___master the language.

校长在晨会上表扬了表现优异的学生。

The ___master praised the outstanding students at the morning assembly.

请把这份文件的原件保存在安全的地方。

Please store the ___master copy of this document in a safe place.