A water-soluble substance is something solid that disappears into water when you mix it in. It does not just break into smaller pieces and sit at the bottom — it truly spreads out through the water and you cannot see it any more. Sugar and salt are the classic examples: put them in a cup of hot water, stir, and they are gone, though the water now tastes sweet or salty, so you know they are still there.

A water-soluble substance is something solid that disappears into water when you mix it inWater-soluble 的物質是指某種固體，混進水裡之後就會消失不見。It does not just break into smaller pieces and sit at the bottom它不是只被打碎成小塊沉在底部 — it truly spreads out through the water而是真正擴散到整杯水裡, and you cannot see it any more讓你再也看不到它。Sugar and salt are the classic examples糖和鹽就是最經典的例子: put them in a cup of hot water, stir, and they are gone把它們放進一杯熱水裡攪一攪，就不見了, though the water now tastes sweet or salty不過這時水嚐起來是甜的或鹹的, so you know they are still there讓你知道它們其實還在。

You meet this word most often in three places. In science class, where things are sorted into water-soluble and not water-soluble (oil is the famous one that refuses).

You meet this word most often in three places你最常在三個地方碰到這個詞。In science class在自然科學課上, where things are sorted into water-soluble and not water-soluble東西會被分成 water-soluble（水溶性）和非水溶性 (oil is the famous one that refuses)（油就是那個有名、不肯溶解的東西）。

On medicine and vitamin packets — vitamin C and the B vitamins are water-soluble, which matters because your body cannot store them well; extra amounts leave in your urine, so you need them regularly.

On medicine and vitamin packets在藥品和維他命包裝上 — vitamin C and the B vitamins are water-soluble維他命C和B群都是水溶性的, which matters because your body cannot store them well這點很重要，因為你的身體沒辦法好好儲存它們; extra amounts leave in your urine多餘的量會隨尿液排出, so you need them regularly所以你需要定期補充。

And on product labels: water-soluble ink, water-soluble glue, water-soluble fertiliser, water-soluble packaging for laundry pods. There the word is a promise about convenience — it will wash out, it will dissolve on its own, you will not have to scrub.

And on product labels還有在產品標籤上: water-soluble ink, water-soluble glue, water-soluble fertiliser, water-soluble packaging for laundry pods像 water-soluble ink（水溶性墨水）、water-soluble glue（水溶性膠水）、water-soluble fertiliser（水溶性肥料）、洗衣球用的水溶性包裝。There the word is a promise about convenience在這裡這個詞是一種方便的保證 — it will wash out, it will dissolve on its own它會被洗掉，會自己溶解, you will not have to scrub你不需要用力刷洗。

The opposite side has two words. `insoluble` means it will not dissolve at all. `fat-soluble` (or `oil-soluble`) means it dissolves in fat or oil instead of water — vitamins A, D, E and K are like this, and that is exactly why those ones CAN build up in your body.

The opposite side has two words相反的一邊有兩個詞。`insoluble` means it will not dissolve at allInsoluble 是指完全不會溶解。`fat-soluble` (or `oil-soluble`) means it dissolves in fat or oil instead of waterFat-soluble（或 oil-soluble）是指它溶在脂肪或油裡，而不是水裡 — vitamins A, D, E and K are like this維他命A、D、E、K就是這樣, and that is exactly why those ones CAN build up in your body這正是為什麼這幾種維他命會囤積在體內。

The word is a little formal and technical; a friend would say 'it dissolves in water', and only a label or a teacher says 'water-soluble'.

The word is a little formal and technical這個詞有點正式、專業; a friend would say 'it dissolves in water'朋友會直接說「it dissolves in water」（它會溶在水裡）, and only a label or a teacher says 'water-soluble'只有標籤或老師才會說「water-soluble」。