攻读
gōng dú · HSK 7
to study a specialty to obtain a higher degree
📚🎓 攻 attack + 读 read = attack the books to earn a degree
攻 (gōng) means attack or assault; 读 (dú) means read or study. Together they mean assaulting your studies — pursuing a specialty hard enough to earn a higher degree.
攻 — 工 (gōng, phonetic) + 攵 (strike/action)
A semantic-phonetic compound: 攵 (a hand holding a stick) gives the meaning of striking or attacking, while 工 supplies the sound. Originally meaning to attack militarily, it later extended to 'work on' or 'study intensively,' as in 攻读.
读 — speech radical 讠 + 卖 (mài, sell)
读 is a semantic-phonetic compound. The left side 讠 (speech) gives the meaning, since reading is tied to speaking words aloud. The right side 卖 originally provided the sound; in the traditional form 讀 the phonetic was 賣 (yù/dú).