periodicadj.周期的；定期的；间歇的；完句的periodic method周期法periodic ptosis周期性上睑下垂periodic motion周期运动periodic audits[经] 定期审计, 定期查帐periodic earing老顶周期来压步距periodic spring周期性泉periodic rating周期性负载额定强度periodic crises周期性危机periodic cracks周期裂缝periodic-buds周期芽孢