题目

Jones, a hardworking blacksmith, used to work all day in his shop. So hard working was he that at times he would make the sparks fly from his    1   .    The son of Mr. Smith, a rich    2   , would come to see the blacksmith every day and for hours and hours he would enjoy himself    3    how the tradesman worked.    Young man, why don't you    4    your hand to learn to make shoe tacks,   5    it is only to pass the time? said the blacksmith.    6    knows, one day, it may be of use to you.    The lazy boy began to see what he could do. But after a little2018年2月25日平昌冬奥会闭幕式上，北京市长陈吉接过巴赫主席转交的五环旗，向全世界宣布冬奥会正式进入北京时间。右图为滑轮鞋的构造，请回答下列问题。（1）所示物质中含有的金属材料是_____（填一种即可，下同），含有的有机合成材料是_____（2）用铝合金做支架的主要优点是____________（3）请用一个化学方程式直接比较铝和铁的活动性_________________