Cách sử dụng
The word 'vein' is used to describe the blood vessels in your body that carry blood to your heart. Veins are all over your body, like roads that carry blood to different parts of your body. You can see veins under your skin, especially in your arms and legs. You can also use the word 'vein' to describe a thin line or streak in something, like a piece of marble or a leaf.