The hard outer layer that wraps round something and keeps it safe. A wire has a rubber casing so you do not get a shock. A phone has a plastic casing; a clock has a metal casing; a bullet has a brass casing that is left behind on the ground. The word is about protection and shape — it holds the thing in and keeps the world out.

The hard outer layer that wraps round something and keeps it safecasing是包住某樣東西、讓它安全的堅硬外層 A wire has a rubber casing電線有橡膠casing， so you do not get a shock讓你不會觸電 A phone has a plastic casing手機有塑膠casing； a clock has a metal casing時鐘有金屬casing； a bullet has a brass casing that is left behind on the ground子彈有黃銅casing，會留在地上 The word is about protection and shape這個字講的是保護和形狀—— it holds the thing in and keeps the world out它把裡面的東西固定住，把外界擋在外面

You meet it most in technical and everyday-mechanical talk: builders, engineers, repair shops, crime programmes on TV.

You meet it most in technical and everyday-mechanical talk你最常在技術性和日常機械相關的話題裡遇到它： builders, engineers, repair shops, crime programmes on TV建築工人、工程師、修理店、電視上的犯罪節目

Two more uses worth knowing. In building, casing is the frame of wood around a door or window. And a sausage casing is the thin skin that holds the meat in — the part that goes snap when you bite a good sausage. All of these are the same idea in different materials: a skin that contains.

Two more uses worth knowing還有兩個值得知道的用法 In building在建築上， casing is the frame of wood around a door or windowcasing是指門窗周圍的木框 And a sausage casing is the thin skin that holds the meat in而sausage casing是包住肉的那層薄薄的皮—— the part that goes snap when you bite a good sausage就是你咬一根好香腸時，會發出啪一聲的那個部分 All of these are the same idea in different materials這些其實都是同一個概念用在不同材質上： a skin that contains一層包住東西的皮

It is a countable noun, so you can say two casings.

It is a countable noun它是可數名詞， so you can say two casings所以你可以說two casings