A.New laws are yet to be made to reduce pollutant release.B.Pollution has attrac
A. New laws are yet to be made to reduce pollutant release.
B. Pollution has attracted little attention from the public.
C. The quality of air will surely change for the better.
D. Itll take years to bring air pollution under control.
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A.He will help the woman with her reading.B.The lounge is not a place for him to
A. He will help the woman with her reading.
B. The lounge is not a place for him to study in.
C. He feels sleepy whenever he tries to study.
D. A cozy place is rather hard to find on campus.
A.A rock climber.B.A psychologist.C.A resident doctor.D.A caree
A rock climber.
B. A psychologist.
C. A resident doctor.
D. A career consultant.
How did the author feel when waiting tables at the age of 19？
A. She felt it unfair to be treated as a mere servant by professionals.
B. She felt badly hurt when her customers regarded her as a peon.
C. She was embarrassed each time her customers joked with her.
D. She found it natural for professionals to treat her as inferior.
已知在混合酚样品中仅含有苯酚、o-甲酚、m-甲酚、p-甲酚四种组分，经乙酰化处理后，测得色谱图，从图上测得各组分的峰高、半峰宽以及测得相对校正因子分别如下：
求各组分的质量分数。
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