搜题请搜索小程序“爱下问搜题”
问题 单项选择题

基础与墙身使用不同材料，位于设计室内地坪( )mm以内时以不同材料为界，超过 ( )mm，应以设计室内地坪为界。

A．±55；±310

B．±100；±500

C．±150；±550

D．±300；±300

答案

参考答案：D

实验题

用下面两种方法可以制得白色的Fe(OH)2沉淀。

方法一：用不含Fe3+的FeSO4溶液与用不含O2的蒸馏水配制的NaOH溶液反应制备。

(1)用硫酸亚铁晶体配制上述FeSO4溶液时还需加入________________。

(2)除去蒸馏水中溶解的O2常采用___________ 的方法。

(3)生成白色Fe(OH)2沉淀的操作是用长滴管吸取不含O2的NaOH溶液，插入FeSO4溶液液面下，再挤出

NaOH溶液。这样操作的理由是_______________

方法二：在下图所示装置中，用NaOH溶液、铁屑、稀H2SO4等试剂制备。

(4)在试管I里加入的试剂是________。

(5)在试管Ⅱ里加入的试剂是___________。

(6)为了制得白色Fe(OH)2沉淀，在试管I和Ⅱ中加入试剂，打开止水夹，塞紧塞子后的实验步骤是_________________

(7)这样生成的Fe(OH)2沉淀能较长时间保持白色，其理由是________________。

查看答案
单项选择题

Shundagarh is a village on India’s east-facing coast. The Khadra Hills rise immediately behind the village, to a height of one hundred and fifty meters. A simple, good-hearted old man, whose name was Jalpur, farmed two small fields on the very edge of those hills. From his fields he could see everything up and down the coast. If the weather was kind and the harvest was good, Jalpur could live happily enough — not well, but happily. When there was little or no rain, then he came close to the line between a life which was too hard and death itself.
Last year the weather had been so kind and the harvest promised to be so good, that Jalpur had been wondering whether he could sell all that he had and live with his son farther up the coast. He had been thinking about doing this for some years. It was his dearest wish to spend his last days with his son and his family. But he would go only if he could give; he would not go if it meant taking food out of the mouth of his grandchildren. He would rather die hungry than do this.
On the day on which Jalpur decided that he would harvest his corn, he looked out to sea and saw a huge wave, several kilometers out, advancing towards the coast and the village of Shundagarh. Within ten minutes everyone in Shundagarh would be drowned. Jalpur would have shouted, but the people were too far away to hear. He would have run down the hill, but he was too old to run. He was preparing to do anything to save the people of Shundagarh, so he did the only thing that he could do. He set fire to his corn. Immediately smoke was rising high. Within a minute the people of Shundagarh were running up the hill to see what had happened. There, in the middle of his blackened corn-field, they found Jalpur; and there they buried him.
On his grave, they wrote the words: Here lies Jalpur, a man who gave, living; a man who died, giving.

How did Jalpur save the village people
[A] He asked the villagers to come out to see what was going on.
[B] He shouted to the people.
[C] He ran down the hills to warn people.
[D] He set fire on his corn to attract people’s attention.
查看答案