血气分析仪内部具有哪两个泵？

阅读理解

       Here's Tom's invitation(请柬)

       It's My Birthday

       I hope you can come to my party

       Time: 7:30 in the evening

       Date: January l0th

       Place: My House(No. 34 Zhongshan Road)

       Tel(H).0713-4331155

1. Tom will have _______ party.                

A. a birthday              

B. an English

C. a family                    

D. a morning

2. Tom's birthday is on ________.

A. January ten                

B. February 10th

C. January tenth              

D. February 12th

3. The party starts ________ .

A. at 7:30 in the evening

B. at 7:00 in the evening

C. at 8:00 in the morning     

D. at 8:30 in the morning

4. Tom will have his party ________ .

A. in Room 34                  

B. in his classroom

C. in his house              

D. at school

软件危机出现于60年代末，为了解决软件危机，入们提出了 【3】 的原理来设计软件，这就是软件工程诞生的基础。

简要论述一价定律(law of one price)在购买力平价(purchasing power parity)理论中的作用。

同时使用EN型和EL型风的非自动观测站，当EN型风日最大风速缺测时，可用EL型风相应记录代替。某时风向风速记录缺测时，如有EL型风记录，则用EL型风相应记录代替。即2分钟风向风速记录缺测时，用EL型风指示器（或轻便风向风速表）观测记录代替；若10分钟风向风速记录缺测时，用EL型风记录器挑取的该时次相应记录代替。（）