Base exchange

Base exchange (BX), also referred to as a post exchange (PX) on Army installations, is a large department store-like shop that operates on United States military installations worldwide. Exchanges on Army and Air Force bases are operated by the Army and Air Force Exchange Service (AAFES), while those on Navy and Marine Corps installations are operated by the Navy Exchange Service (NEX) and the Marine Corps Exchange (MCX). The Coast Guard Exchange (CGEx) operates a handful of stores on Coast Guard installations.
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B: (Kimia) penukar basa
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Eng: base exchange
Urdu: تبادلہ اساس ۔ کِسی ایک کیمیائی اساس کو نِکال کر کِسی دُوسری کیمیائی اساس کو شامِل کرنا ۔