Perfectly
来自Big Physics
Middle English: from Old French perfet, from Latin perfectus ‘completed’, from the verb perficere, from per- ‘through, completely’ + facere ‘do’.
wiktionary
perfect + -ly
etymonline
perfectly (adv.)
c. 1300, parfitli, "completely, thoroughly, wholly;" see perfect (adj.) + -ly (2). Meaning "flawlessly, in perfect form or manner" is from late 14c.