椎体
参考答案:
硬骨鱼类的椎体为双凹椎体,凹处有退化的残余脊索存在。
根据句意和首字母提示填空,完成下列句子。
1. Please show me your driver l_______.
2. Children under eighteen are not a_______ to buy alcohol. (酒精饮料)
3. Tom is always s_______ with his children.
4. Does he speak Italian well e_______ to get the job?
5. Jimmy never f_______ to arrive on time.
6. I will phone you s_______ this evening.
7. Students should c_______ more on their studies.
8. My sister is ten years old. She studies in a p_______ school.
9. If you keep on trying you will s_______ in the end.
10. One of my friends v_______ to take us all in his car.
在市场经济条件下,物业管理的属性是经营,所提供的商品是( )。
A.管理
B.劳务
C.服务
D.经济