Yabla video uses of 钻研

柴门 cháimén
Huò
从小 cóngxiǎo
jiù
开始 kāishǐ
le
duì
语言 yǔyán
de
钻研 zuānyán
Zamenhof began studying language intensively from a young age.
一直 yīzhí
dōu
zài
钻研 zuānyán
技术 jìshù
after continuously delving into techniques,