我国劳动人民早在春秋战国时期就已经懂得钢铁冶炼，铁也是生活中使用最为广泛的金属，目前我国钢铁产量已经位居世界第一。下面是一组有关铁的问题，请你用所学化学知识加以回答：
（1）用赤铁矿（Fe₂O₃）炼铁的化学反应方程式是____ 。成语“千锤百炼”就源于生铁炼钢的过程，该过程中发生化学反应的化学方程式是____ 。
（2）铁可以拉成铁丝，压成铁片，这是利用了铁的____性；在公路上行驶的油罐车尾部经常有一条铁链拖在地面上，这是利用了铁的____性；家里铁制炊具要有木柄或塑料柄，这是因为铁有很好的____ 性。
（3）焊接钢管时，经常用硫酸铜溶液在钢管表面画交叉线，然后根据出现的红线对准焊接，用化学方程式表示反应原理____ 。
（4）经研究发现，长期使用我国发明的铁锅炒菜做饭，可有效地减少缺铁性贫血的发生，如果在炒菜时经常加入适量的食用醋，效果会更好，理由是____ 。
（5）某同学在做盐酸和锈铁钉反应实验时，发现含锈的铁钉表面出现了气泡，你觉得原因是____ 。

已知：R﹣CH=CH₂ $\underset{②H_2{O}_2/O{H}^{-}}{\overset{①B_2{H}_4}{\to }}$ R﹣CH₂CH₂OH

①每个公民在公民大会上都有表决权

②为参加政治活动的公民发放津贴

③排除妇女和外邦人的国家决策方式

④抽签选举和轮流坐庄的参政方式

   Mr. Green worked in an office in London, but he lived in the country and came to work by train every day. The station was not very far from his office, and he always went on foot from the station to his office and back from his office to the station. Every evening he walked past a poor man near a bridge. The man sat at the road and sold matches, and there was a dog near him. There was a piece of wood round the dog’s neck, and the words “I AM BLIND” were on the piece of wood.
   Mr.Green was a kind man. He always stopped and gave a penny to the man, but he did not take any of his matches. One day, Mr.Green had a lot of work in his office and left the office very late. He came to the man and his dog, but he did not stop. The poor man stood up quickly, ran after him and said, “You’re always very kind to me. Give me a penny today. I’m a poor man.” Mr.Green stopped and he was surprised. Then he said, “You’re a blind man. How did you see me?” The poor man said, “No, I’m not blind. My dog is.”