关于血红蛋白（Hb）与O₂结合特征的叙述，下列哪一项是正确的（）

A. 525

B. 725

C. 475

D. 500

A. 技术项目

B. 措施项目

C. 零星项目

D. 取费项目

A. 它利用计算机来模仿人的高级思维活动

B. 它可以执行单靠人力无法完成的任务

C. 它根据公式或模型进行很大数量的计算工作

D. 它利用数字化技术和人机交互技术，提供多种信息表现形式

A. 80

B. 65

C. 73

D. 60

A. 纳税人

B. 征税对象

C. 税率

D. 计税依据

A. 75

B. B.75.5

C. C.78.5

D. D.81

-- ________.

A Great B

Don’t worry

C That’s fine

D Not at all

A.当0<50%时，表明经济景气循环进入衰退阶段<>

B.当50%<100%时,表明经济景气循环进入复苏阶段<>

C.当100%>DIt>50%时，表明经济景气循环进入繁荣阶段

D.当50%>DIt>0时，表明经济景气循环进入萧条阶段

E.当50%>DIt>0时，表明经济景气循环进入复苏阶段

Hi, I am Zhao Xin from Beijing. I just enrolled at The Open University last month. Now I'm a freshman at. the School of Social Work. As a social work major, I can help take care of the homeless and sick people, talk to them and accompany them, do the cleaning and other house chores. I enjoy helping people and want to live a meaningful life.

I love being a social worker. I used to look after the elderly at a nursing home when I was in middle school. It gives me a feeling of pride to bring happiness to others. I want to make a difference in the world.

()26. Zhao Xin is studying in the Open University now.

()27. His major is marketing.

()28. He is looking after the elderly at a nursing home nowadays.

()29. He .wants to change the world and make it better.

()30. He is proud of being a social worker.

A200ml

B300ml

C400ml

D>400ml

E>600ml