一杯牛奶用英语可以说成 "a glass of milk"。

"Milk" 这个词来源于古英语中的 "meoluc"，是指用来喂养婴儿的乳液。

例句：

Can I have a glass of milk, please?

A glass of milk is a good source of calcium.

I like to have a glass of milk before going to bed.