为新疆各族人民在维护国家统一原则下，充分行使自治权利，自主管理地方事务，平等参与管理国家事务，提供有力制度保障的基本政治制度是（    ）

人因大量出血而需输血时，应以输入____为原则．

AMary: Hello, Gina. Do you want to have evening classes? On Monday evenings, there is a guitar (吉他) class.

Gina: I'm busy on Mondays. What about Tuesdays?

Mary: There's a class to teach you how to make bread. The teacher is Mr. Smith.

Gina: The class is useful. And Mr. Smith's bread is great. And Wednesdays?

Mary: That class is about clothes. You can learn how to make clothes.

Gina: It's fun. What class do you want to take?

Mary: Well, on Thursdays, there's one interesting class. I can learn how to make model planes.

Gina Oh, that's great. But I'm busy those days.

Mary: There is another (另一) interesting class on Friday evenings. You can learn about the stars.

Gina: It's boring. Is there a class on Saturdays?

Mary: Yes, you can learn how to take pictures.

Gina: Great! I like this class. I'll take it.

根据材料内容选择最佳答案。