p.a.

p.a.

名词 p.a.:

an electronic amplification system used as a communication system in public areas

同义词：public address system, P.A. system, PA system, PA

an informal term for a father; probably derived from baby talk

同义词：dad, dada, daddy, pa, papa, pappa, pop

a short-lived radioactive metallic element formed from uranium and disintegrating into actinium and then into lead

同义词：protactinium, protoactinium, Pa, atomic number 91

a unit of pressure equal to one newton per square meter

同义词：pascal, Pa

a Mid-Atlantic state; one of the original 13 colonies

同义词：Pennsylvania, Keystone State, PA

副词 p.a.:

by the year; every year (usually with reference to a sum of money paid or received)

同义词：per annum, per year, each year, annually