脊柱有四个______，分别是______，______，______，______．
正常成年人的脊柱自颈椎至骶椎有4个生理性弯曲，即向前凸的颈曲与腰曲，向后凸的胸曲与骶曲．
从侧面看脊柱呈“S”形弯曲．脊柱的生理性弯曲可使脊柱产生弹性动作，以缓冲和分散在运动中对头和躯干产生的震动，故脊柱的弯曲具有生理性保护作用．
故答案为：生理弯曲；颈曲；腰曲；胸曲；骶曲
| 选择正确的译文或答语。 |
| 1. 这是桔汁。 |
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| A. This is an orange juice. B. This is orange juice. C. This is orange. |
| 2. 这是一只棕色的猴子。 |
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| A. This is a brown monkey. B. This is a blue monkey. C. This is a brown donkey. |
| 3. 我喜欢看书。 |
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| A. I like reading book. B. I like to read books. C. I like to see books. |
| 4. —Nice to meet you. — . |
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| A. Nice to see you. B. Nice to meet you, too. C. Good-bye. |
| 5. —How old are you? — . |
[ ] |
| A. I'm eleven. B. How are you? C. It's black. |