根据所学知识回答下列与金属材料、碳和碳的氧化物有关的问题．

（1）小童将观察到的现象形象的画了一幅卡通画，如图所示，每个卡通人物表示一种金属，周围的小黑点表示反应中生成的气体，四种金属的活泼性由强到弱的顺序是____ ．

（2）小童要用其它方法比较铜、铁、镁的活动性顺序，他已经选择了打磨过的镁丝和铜丝，你认为他还需要选择的另外一种溶液是____溶液．

（3）铜粉中混有少量的铁粉，除去铁粉的物理方法是____．

（4）钢铁是用量最大、用途最广的含____量不同的铁合金．

（5）物质的用途体现物质的性质，单质碳和一氧化碳都能用于冶炼金属，该用途体现了单质碳和一氧化碳都具有____性．

（6）碳的氧化物有一氧化碳和二氧化碳，将二氧化碳沿右图所示装置慢慢倒入烧杯中，观察到的现象是蜡烛____依次熄灭，由此可以证明二氧化碳的密度比空气大．

（7）保护金属资源的有效途径之一是防止金属的腐蚀，请你写出一条防止家里菜刀生锈的具体方法____．

①氢元素____②氧元素____③铁元素____④镁元素____ ⑤氧气____⑥氮气____⑦铜____⑧锌____ ⑨水____⑩二氧化硫____

    Jack is a 16-year-old boy. Last summer, he wanted to have a nice1.He asked his parents for the money.But his parents said he must get it by himself.But 2could he get one?

    One day，on his way home，he was thinking about this.Not many people wanted to ask children to work3them.Maybe he could sweep away the snow for the neighbours.However，it was not4.He had to wait a long time for that. Just at the moment，he saw Tom，one of his classmates，working in a5shop.

    "I could do that，"he thought.He asked Tom some questions.He learned that it took Tom about three hours a day to do the job6he could get twenty dollars each week.Then Tom gave him the telephone number of the book shop manager.Jack almost 7 home."Mum，I have good news to tell you，"Jack said.After he told his mother that，she said,"I think it's a8idea."

    "I will9the manager tomorrow,"said Jack，"After all，I'm going to be a businessman.''Jack's mother looked 10at him and smiled.

    After the summer holiday，Jack got the bike which he dreamt of.