1、牛奶的分类：

首先我们进入超市，想询问是否有自己想要的牛奶时，要怎么说呢？

Excuse me, do you have non-fat milk here?
不好意思，请问你们这有无脂牛奶吗？

Whole milk/Regular milk
全脂牛奶，脂肪含量3.25%

Whole milk -- also known as regular milk-- has the most amount of milk fat as any other type of milk.
全脂牛奶是 —— 所有牛奶中乳脂含量最高的。

This type of milk has no process to remove the milk fat.
这种牛奶没有脱脂。

So, in the end, regular milk has about 3.25% of milk fat and the most calories because of that extra fat.
所以最后这种牛奶有3.25%的乳脂含量，也因为多余的脂肪，卡路里含量最高。

2% milk

This type of milk is considered to be "reduced fat".
这种牛奶是“减脂”的

It has less milk fat than normal milk, but it tastes almost as creamy as whole milk.
它比普通牛奶的脂肪含量少，但和全脂牛奶的口感差不多。

2% milk is just as popular as normal whole milk.
2%牛奶和全脂牛奶一样受欢迎。

1% milk

1% milk is a lowfat milk, it has less fat than 2% milk.
1%牛奶是一种低脂牛奶，它的脂肪含量比2%牛奶还低。

A lot of people choose this kind of milk if they want to go on diets.
很多要控制饮食减肥的人都会选择这种牛奶。

Skim milk/skimmed milk
脱脂牛奶

Our final type of milk is called "non-fat" milk or skim milk. This type of milk is also known as "skimmed milk."
最后一种是脱脂牛奶，可以被叫做“non-fat mik”, "skim milk"或者“skimmed milk”。

This type of milk has as much fat as possible removed from the milk. This makes nonfat milk have less calories than normal milk. It still has all of the nutrients though.
这种牛奶里的脂肪被最大限度去除了，所以脱脂牛奶比普通牛奶的脂肪含量低，但却有相同的营养成分。

So, if you want non-fat milk and aren't sure if the store has it, you can ask a worker: "Excuse me, do you have non-fat milk here? or Excuse me, do you have skim milk here?"
如果想买脱脂牛奶但不确定店里是不是有，可以问：不好意思，请问你们这有脱脂牛奶吗？