问题
单项选择题 A1/A2型题
在气相色谱法中，当升高柱温时（）。
A.保留时间缩短
B.分离度提高
C.保留时间增加
D.分离度下降
E.分析速度加快
答案
参考答案：A
解析：柱温越高，检测物与固定相吸附越不牢，在柱内流动也越快。
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在气相色谱法中，当升高柱温时（）。
A.保留时间缩短
B.分离度提高
C.保留时间增加
D.分离度下降
E.分析速度加快
参考答案：A
解析：柱温越高，检测物与固定相吸附越不牢，在柱内流动也越快。
It was in my high school science class. I was doing a task in front of the classroom with my favorite shirt on. A came, “Nice shirt,” I smiled from ear to ear. Then another voice said, “That shirt belonged to my dad. Greg’s mother works for my family. We were going to that shirt away, but gave it to her .”I was speechless. I wanted to hide. I the shirt in the back of the closet and told my mum what had happened. She then dialed her , “I will no longer work for your family,” she told him. That night, Mom told my dad that she couldn’t clean anymore; she knew her life’s was something greater. The next morning she with the personnel manager at the Board of Education. He told her that without a proper education she could not teach. So mom decided to a university. After the first year in college, she went back to the personnel manager. He said, “You are __ , aren’t you? I think I have a for you as a teacher’s assistant. This opportunity deals with children who are mentally challenged with little or no chance of .” Mom accepted the opportunity very . For almost five years, as a teacher’s assistant, she saw teacher after teacher give up on the children and quit, feeling . Then one day, the personnel manager and the principal __ _ in her classroom. The principal said, “We have watched how you the children and how they communicate with you and admire your hard – working over the last five years. We are all in agreement that you be the teacher of this class.” My mom spent more than 20 years there. her career, she was voted Teacher of the Year. All of this came about because of the comment made in the classroom that day. Mom showed me how to handle situations and never give up.
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