某男孩，近半年感觉疲倦，头晕，乏力，心悸，呼吸急促，查血红蛋_爱下问搜题

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问题单项选择题

某男孩，近半年感觉疲倦，头晕，乏力，心悸，呼吸急促，查血红蛋白90g/L，红细胞平均体积82fl，原卟啉大于500μg/L，其最可能的原因是

A．钙缺乏
B．铁缺乏
C．叶酸缺乏
D．锌缺乏
E．维生素B12缺乏

答案

参考答案：B

完形填空

完形填空（共20小题；每小题2分，共40分）
There was a woman in Detroit, who has two sons．She was worried 36 them, especially the younger one, Ben, 37 he was not doing well in school． Boys in his class 38 fun of him because he seemed so   39 ．
The mother  40 that she herself, would have to get her sons to do better in school．She  41   them to go to the Detroit Public Library to read a  42 a week and do a report about it for her．
One day, in Ben’s  43 , the teacher held up a rock and asked if anyone knew it. Ben 44 up his hand and the teacher let him 45 ．“Why did Ben raise his hand?” they wondered． He   46 said anything; what could he possibly want to say?
Well, Ben not only 47 the rock; he said a lot about it． He named other rocks in its group and even knew 48 the teacher had found it． The teacher and the students were 49 ． Ben had learned all this from doing one of his book   50 ．
Ben later went on to the   51 of his class．When he finished high school, he went to Yale University   52 at last became one of the best doctors in the United States．
After Ben had grown up, he   53 something about his mother that he did not know as a   54 ．She, herself, had never learned how to   55  ．

选择题

某同学通过实验比较四种金属的活泼性大小。他取等质量的金属粉末分别与等质量分数的足量稀盐酸反应，将实验的结果记录在下表中，由此得出的实验结论正确的

金属	是否放出气体	收集20ml气体所需时间
X	是	4s
Y	不	/
Z	是	43s
W	是	97s

A．W是最不活泼的金属 B．四种金属的活泼性顺序为X>Z>W>Y

C．放出的气体一定是纯净的氢气 D．在相同的反应时间里，W产生的气体最多