等腰三角形底边上的高等于底边的一半，则这个等腰三角形的顶角度数是[ ]

A．30°

B．45°

C．90°

D．120°

根据词意和所给的第一个字母写出相应的单词

1. not very often s________

2. the food you usually eat d________

3. a person who dances d________

4. costing a lot of money e________

5. like something or someone better p________

6. the way you live l________

7. a cut in price d________

8. power to do things e________

9. go well with m_________

10. usually with bright colours f________