tā / jīng / guò / duō / nián / xùn / liàn / yǐ / jīng / jīng / shú / de / zhǎng / wò / le / zhè / mén / jì / yì

他经过多年训练，已经精熟地掌握了这门技艺。

After years of training, he has become highly proficient in this craft.