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【简答题】
今年十月份，我校九年级的同学们都做了“氧气的制取与性质”这个分组实验。同学们在螺旋状的细铁丝末端系上一根火柴梗，将它固定，用镊子夹住铁丝，然后将火柴在酒精灯上点燃，待火柴梗即将燃尽时，将它们由集气瓶口向下慢慢伸入，观察现象： ⑴甲同学发现铁丝在收集到的氧气中燃烧起来，观察到火星四射，放热，并有黑色固体生成，请写出该反应的化学式表达式 ； ⑵乙同学只发现铁丝红热一下，就没有观察到其它现象，请你分析铁丝没有燃烧的可能原因是 ；(只答一条) ⑶丙同学在做实验时，集气瓶炸裂了，请你帮助他分析一下原因： 。
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【简答题】在298K时，某溶液含MgCl 2 和ZnSO 4 的浓度均为0.002mol·kg -1 ，试用Debye-Htickel极限公式求ZnSO 4 的离子平均活度因子。
【简答题】298 K 时,在 0.002 mol · kg -1 CaCl 2 和 0.002 mol · kg -1 ZnSO 4 混合液中, Zn 2+ 的活度系数为多少 ? 已知 : A = 0.509(mol · kg -1 ) -1/2
【单选题】在用反相HPLC法分离测定B族维生素时常加入己磺酸钠,其目的是
A.
调节溶液的PH值，使样品充分游离
B.
与样品离子反应生成离子对，改善色谱行为
C.
防止样品被氧化
D.
络合样品中微量的金属离子
E.
抑制B族维生素电离
【单选题】The author would most likely agree with which of the following descriptions of the conflict between Darwinists and cultural anthropologists over the nature of animal emotions?
A.
The concept of animal emotions suggests that human emotions are based on instinctual biology.
B.
Cultural relativists dispute the notion that animal emotions are innate and not be learned.
C.
Darwinists view the s of the twentieth-century as a triumph of animal instinct over rational human behavior.
D.
Darwinists wish to draw a line between emotional behavior. and culturally acquired behavior.
E.
Cultural relativists support the idea of an animal behavior. dictated by behavioral rules.
【单选题】Jack Kerouac was neither a demon nor a saint but a ______ , notably gentle, deeply conflicted and finally self-destructive person whose dream from childhood was to be a writer.
A.
muse
B.
martyr
C.
cadge
D.
fallible
E.
ascetic
【简答题】MDY({^1999-12-30})，显示结果为______。
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