词根词缀：-enni-, -ennial, -ennium

【来源及含义】Latin: year, years

【同源单词】aere perennius, amillennialism, annual, biannual, bicentennial, biennia

词根词缀：per-

【来源及含义】Latin: through, across, over; beyond, by means of

【同源单词】Ad astra per aspera, Ad augusta per angust, Ad perpetuam rei memoriam, Ad virtutem per sapientiam, ampersand, antiperspirant