On a US military base, the PX is the shop. Soldiers and their families buy food, clothes, soap, snacks, electronics — ordinary life, not weapons.

On a US military base在美軍基地裡 the PX is the shop PX 就是那間福利社 Soldiers and their families軍人和他們的家人 buy food, clothes, soap, snacks, electronics會在那裡買食物、衣服、肥皂、零食、電子產品 ordinary life, not weapons都是日常用品，不是武器

The letters come from post exchange: post here means the base, and exchange is an old army word for that shop.

The letters come from post exchange這幾個字母來自 post exchange post here means the base這裡的 post 指的是基地 and exchange is an old army word for that shop而 exchange 是軍隊裡對這種商店的老說法

Prices are often lower than outside because of tax rules on the base, and you cannot just walk in if you are not allowed on the base.

Prices are often lower than outside價格通常比外面便宜 because of tax rules on the base因為基地上有稅務上的優惠 and you cannot just walk in而且你不能隨便走進去 if you are not allowed on the base如果你沒有進入基地的許可

Air Force bases sometimes say BX instead; the Navy often says the Navy Exchange. In films set on American bases, someone will say they will be at the PX. Taiwan students already know 福利社 from school; this is that idea, but on a US base, and the letters PX are the American name.

Air Force bases空軍基地 sometimes say BX instead有時候會改說 BX the Navy often says the Navy Exchange海軍則常說 Navy Exchange In films set on American bases在以美軍基地為背景的電影裡 someone will say they will be at the PX會有人說他要去 PX Taiwan students already know 福利社 from school台灣學生從學校就已經知道「福利社」這個概念 this is that idea這裡講的就是同一個概念 but on a US base只是搬到了美軍基地上 and the letters PX are the American name PX 這幾個字母就是美式的說法