The body's circulatory system includes the heart and blood vessels. The heart pumps blood to all parts of the body through a network of arteries and veins.
人體的循環(huán)系統(tǒng)包括心臟和血管，心臟通過動脈和靜脈網絡將血液輸送至身體各部位。

The digestive system breaks down and absorbs food into the body. It's supplies the energy that the body needs for growth and repair. After digestion, excess food is turned into waste and eliminated from the body.
消化系統(tǒng)分解，為人體吸收食物養(yǎng)分，提供人體生長和修復所需的能量。消化后，多余的食物轉換為廢物，從體內排出。

The nervous system includes the brain, spinal cord and nerves. This is your body's control system. It controls your muscles and organs, including your circulatory and digestive systems.
神經系統(tǒng)包括大腦、脊髓和神經——這是人體的控制系統(tǒng)?？刂萍∪夂推鞴?，包括循環(huán)和消化系統(tǒng)。

The respiratory system includes the nose and lungs. It brings air and oxygen into the body and removes carbon dioxide. The lungs are where oxygen enters the blood stream, and carbon dioxide is removed.
呼吸系統(tǒng)包括鼻子和肺，它將氧氣帶入人體，并清除二氧化碳。肺是氧氣進入血液，排出二氧化碳的場所。

The immune system protects the body against infections and diseases. Sneezing and fever are examples of how the immune system works. If an infection invades the body, the immune system attacks it.
免疫系統(tǒng)保護人體免受感染和疾病，打噴嚏和發(fā)燒就是免疫系統(tǒng)工作的表現(xiàn)。如果感染入侵人體，免疫系統(tǒng)就會攻擊它。