periodicKK [ˏpɪriˋɑdɪk] /ˌpɪɹiˈɑdɪk/发音形容词1定期的、周期性的The machine requires periodic maintenance to stay in good condition.这台机器需要定期保养才能维持良好状态。2间歇性的、不时发生的We still get periodic power outages during the summer months.夏季期间我们还是会间歇性地停电。3周期的化学Every element in the periodic table has an atomic number.周期表上的每个元素都有原子序。用这个字练口说→