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问题 单项选择题 A1/A2型题

解剖无效腔气量约为（）

A.50ml

B.100ml

C.150ml

D.200ml

E.250ml

答案

参考答案：C

解析：正常人潮气量为500ml，其中在呼吸性细支气管以上气道中的气量不参与气体交换，称为解剖无效腔，约为150ml。

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I was always told that the three Ps, patience, positive thinking and perseverance（毅力），were a sure path  31              success. But this advice does not always work as planned. My high school maths exam is one example. The exam,    32             was originally to be held in our classroom,  33           (change) to the library at the last minute. This,  34           ，didn’t bother me because maths had always been my strongest subject. I patiently walked to the library, took my seat and did some deep breathing to help relax   35        ．But my mood quickly changed when I saw  36          first question. I had no idea how to do it. I tried to stay positive and persevered   37         I finally found the solution. With the problem 38         (solve), I felt proud of my achievement.  39       (fortunate), I then noticed that I had just 10 minutes left   40            (complete) the rest!
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单项选择题

科学研究的基本阶段是（）。

A.发现问题和解决问题

B.选题、立项和结题

C.研究结题、研究实施、研究立项

D.研究立项、研究实施、研究结题
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