铬(Cr)为不锈钢主要的添加元素，含量一般在12％以上。铬的表面生成一薄层致密的钝态氧化物保护膜是不锈钢具有耐蚀性主要原因。请回答下列问题：
(1) 铁生锈的主要条件是铁与____ 和____ 直接接触。
(2) 不锈钢是一种____ （填“合金”或“金属”）。
(3) 相同温度下，取大小相同、表面光亮的Cr、Mg、Cu三种金属薄片，分别投入等体积等溶质质量分数的足量稀盐酸中（反应中Cr显+2价），现象如下：

① 上述三种金属的活动性由强到弱的顺序是____ 。
② 从上述探究实验可知，Cr____ （填“能”或“不能”）跟硫酸铜溶液反应。若反应，请写出反应的化学方程式____ 。

综合填空  
从下面方框中选择适当的词，并用其正确形式填空，方框中有两个多余的词。

    Brian likes jogging (慢跑). He jogs in the park every morning. He always brings five dollars with him. He always buys breakfast for

____  in the shop.
    One day he jogged into the park and another jogger knocked into him. A few minutes____, he found his five-dollar bill wasn’t in his pocket. “The man might be a thief!” He thought, “It must be him that took my money. I must fight against the crime (犯罪)! ”
    The man was only 30 meters ahead. Brian ran after him, hit him on the shoulder, and said “Give me the money!”The man was ____ , but at last he gave Brian a five-dollar bill. Then he ran away as fast as he could!
    Brian felt really good and ran to the shop. He had got his money back. He ____ himself a cup of coffee and two hamburgers.
Then he ran back home. His wife was waiting for him. She was shaking her head. “Oh, dear!”she said, "You've had

a ____  morning, haven't you ?”
   “No! Why? I've had a very good morning!”he said. “Really?" she said. “But you left your five-dollar bill on the table!”

圆锥的底面积一定，高和体积成正比例。

如图，是做课间操时，小明，小刚和小红三人的相对位置，如果用（4，5）表示小明的位置，（2，4）表示小刚的位置，则小红的位置可表示为（　　）

不用天平，只用量筒，要量出200g的酒精，应该在量筒内装入体积是　 ____　cm³酒精．（酒精的密度是0.8×10kg/m³）