[计] 预防性服务

Preventive \Pre*vent"ive\, a. [Cf. F. pr['e]ventif.]
1. Going before; preceding. [Obs.]

Any previous counsel or preventive understanding.
--Cudworth.

2. Tending to defeat or hinder; obviating; preventing the
access of; as, a medicine preventive of disease.

Physic is either curative or preventive. --Sir T.
Browne.

{Preventive service}, the duty performed by the armed police
in guarding the coast against smuggling. [Eng]