4 Your Body

Your body

你的身体

Your amazing body. Your body is like a complicated machine, always working to keep you alive. Computer scans can show the different parts that make up a person's body.

你神奇的身体。你的身体就像一台复杂的机器，一直在工作以维持你的生命。 计算机扫描可以显示组成人体的不同部位。

Bony frame. Your skeleton is a frame of bones that gives your body shape and covers its soft parts. You were born with about 300 bones. Many of them join together as you grow. Adults have 206 bones. Femurs are the biggest bones.

骨框架。你的骨骼是一种骨骼框架，它赋予你的身体形状，并覆盖身体的柔软部分。 你生下来就有300块骨头。 随着你的成长，它们中的许多会结合在一起。 成年人有206块骨头。股骨是最大的骨头。

Places where bones meet are called joints. Joints let you bend and twist. Straps called ligaments hold bones together. A slippery liquid helps bones move smoothly.

骨头相交的地方叫做关节。 关节可以让你弯曲和扭动。 被称为韧带的带子将骨头连接在一起。 一种光滑的液体有助于骨骼平稳移动。

Mighty muscles. Muscles are rubbery and stretchy. They are often attached across two bones and help the bones move. When one muscle tightens, it makes a bone move. Then another muscle tightens to move the bone back.

强大的肌肉。肌肉是有弹性的。 它们通常连接在两根骨头上，帮助骨头移动。 当一块肌肉收紧时，它会使一块骨头移动。 然后另一块肌肉收紧，将骨头往后移动。

This picture shows the muscles in your arm and hand. They pull on bones so that you can move your elbow, wrist and fingers. You have about 60 face muscles. They let you make lots of expressions.

这张照片显示了你手臂和手的肌肉。 它们拉动骨头，这样你就可以移动你的肘部、手腕和手指。 你有大约60块面部肌肉。 他们让你做出很多表情。