When we have small cuts in the skin(皮肤), something strange may happen. The cuts are able to heal(痊愈) themselves in a couple of days. How does this happen? Read on, and you will find out the secret.
Every living thing on the earth is made up of cells(细胞). Cells grow and make new cells. Most cells are very small and we can't see them with our eyes. Different cells have different uses. Our skin cells are special ones. The cells on the outside of our skin are old dead cells. New skin cells are right under the outside. These are the living skin cells. They work for our bodies. They help protect our bodies and heal cuts.
Our bodies make skin cells all the time. As the old cells fall off, new cells grow in the same place. Each person makes about 18 kg of skin cells during his or her life. Outside skin cells fit together closely with no gaps between them. When you cut yourself, you can harm your skin cells. A small cut will not be harmful. Your skin will quickly heal itself by making new skin cells. How do skin cells work? First, the cells near the cut get bigger and move into the gap. Next, these bigger cells meet in the middle. They form a new layer(层) of skin cells. Finally, new cells will grow until the gap disappears. In this way, your skin can grow and get well itself. How amazing the small cells are! Next time you have a cut, don't worry about it. Maybe in a few days, you will be surprised to find it healed.
【小题1】The underlined word “gaps” in the passage means “ ” in Chinese.A．突起B．条纹C．缝隙D．代沟【小题2】From the passage, we know that cells .A．are large and we can see them with our eyesB．can heal few cuts themselvesC．are in everything on the earthD．can grow and make new cells【小题3】Skin cells heal cuts in three steps. is the right order.
【小题4】Which of the following is TRUE according to the passage?A．Each person can make 18 kg of skin cells every day.B．Different cells have different uses in our bodies.C．The skin cells have little work to do in the body.D．Every living thing on the earth is made up of skin cells【小题5】The best title for this passage should be .A．How Skin Cells Heal CutsB．The Importance of SkinC．How to Protect Our FingersD．The Importance of CellsC
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(答案→)C
解析：这篇短文主要介绍了人体皮肤的作用，重点介绍了皮肤上的伤口愈合的过程。
【小题1】联系上文Outside skin cells fit together closely with no ，皮肤外细胞密切配合，没有……，可知此处指的是缝隙，故选C。
【小题2】根据第二段Cells grow and make new cells. 描述，可知选D。
【小题3】根据最后一段How do skin cells work? First, the cells near the cut get bigger and move into the gap. Next, these bigger cells meet in the middle. They form a new layer(层) of skin cells. Finally, new cells will grow until the gap disappears.描述，可知选B。
【小题4】根据第二段Different cells have different uses. 描述，可知选B。
【小题5】这篇短文重点介绍了皮肤上的伤口是如何愈合的，故选A，皮肤是如何治疗伤口的。