preventiveadj.预防的；防病的n.预防物；预防性措施preventive test预防性试验preventive laws预防性立法preventive works充水因素preventive trial预防性试验preventive check预防性抑制preventive means预防手段preventive method防治方法preventive target预防目标preventive strike预防性打击preventive safety预防性安全措施