SD is the written short form of South Dakota, one of the fifty US states, in the north of the country, west of Minnesota and east of Wyoming.

SD SD is the written short form of South Dakota是South Dakota（南達科他州）的書面縮寫， one of the fifty US states是美國五十州之一， in the north of the country位在美國北部， west of Minnesota and east of Wyoming在明尼蘇達州西邊、懷俄明州東邊。

You will see the two letters on envelopes, forms, maps, and car plates: an address might end Rapid City, SD. In careful speech you still say the full name, South Dakota; people read the letters aloud mainly when they are looking at a list or filling a box that only has room for two letters.

You will see the two letters你會在 on envelopes, forms, maps, and car plates信封、表格、地圖，和車牌上看到這兩個字母：an address might end Rapid City, SD一個地址可能會以Rapid City, SD結尾。In careful speech在正式一點的說話場合 you still say the full name, South Dakota你還是會說全名South Dakota；people read the letters aloud mainly when they are looking at a list人們會把這兩個字母唸出來，主要是在看一份清單的時候 or filling a box that only has room for two letters或是填一個只有兩個字母空間的欄位時。

Though actually those same two letters do many other jobs in English — a memory card is an SD card, and statistics uses SD for something else — so the meaning hangs on where you see it.

Though actually不過事實上 those same two letters do many other jobs in English這兩個字母在英文裡還做很多其他的工作 — a memory card is an SD card記憶卡叫做SD card， and statistics uses SD for something else統計學也用SD來指別的東西 — so the meaning hangs on where you see it所以意思要看你在哪裡看到它。

In a US address, a state list, or a map of the States, SD is this state.

In a US address, a state list, or a map of the States在美國的地址、州名清單，或美國地圖上， SD is this state SD就是指這個州。