柯林斯詞典periodic /?p??r???d?k/ 1. ADJ Periodic events or situations happen occasionally, at fairly regular intervals. 周期性的 Periodic checks are taken to ensure that high standards are maintained. 進(jìn)行周期性檢查以確保高標(biāo)準(zhǔn)得以維持。 返回 periodic劍橋詞典happening repeatedly over a period of time 周期（性）的；定期的 He suffers periodic mental breakdowns . 他周期性地精神失常。 返回 periodic