慢性肺心病缓解期的主要表现是A．感染表现 B．慢阻肺表现 C．心力衰竭表现 D．呼吸

用所给词的适当形式填空。

1. The Chinese like ____________(eat) different kind of food.

2. What day ____________(be) it last weekend?

3. She can ____________(speak) much English.

4. It's cold outside. ____________(not open) the door, please.

5. My sister ____________(like) English very much.

6. Peter ____________(see) an interesting talk show on TV just now.

7. Look, they ____________(make) kites.

8. I get up at about 6:00. Then I ____________(take) the number 8 bus to school.

9. Jim would like ____________(play) computer games.

10. Last week the teacher asked ten students what they ____________(do) last weekend.

11. Autumn comes after s____________.

12. It's too cold. Please keep the window ____________(关着)

13. Listening to some light music is really ____________(轻松的).

14. I don't like to wear s____________ in winter because my neck is short.

15. Do you mind my ____________(打开) the windows?

16. He practices ____________(play) the guitar every Sunday.

17. In autumn, ____________(树叶) turn yellow.

18. The weather was cool. so we decide ____________(stay) at home.

19. On my way home I found a little girl ____________(cry) in the corner.

20. Last Sunday, I s____________ geography late.

下列关于X2分布的表述，正确的是

A．X2取值永远不会大于0

B．其均值等于其自由度

C．随着自由度的增大，X2分布趋于正偏态

D．多个标准正态分布变量的线性组合所得的新变量符合X2分布

传染病的基本特征是：

A．有传染性、流行性、免疫性、病原体

B．有传染源，传染性，流行性，免疫性

C．有传染源，传播途径，易感性，免疫性

D．有传染性，流行性，地方性，易发性

E．有病原体，传染源，流行性，免疫性

茶树性喜温暖、湿润，在南纬50°与北纬40°间都可以种植。（）

述左心室长轴切面的心脏结构。