题干

将一定质量的铁粉加至H2SO4、MgSO4和CuSO4的混和溶液中,充分反应后过滤,得到滤液M和滤渣N,下列有关说法中,不合理的是(   )

A:滤液M中一定存在Fe2+

B:滤渣N的质量一定小于加入铁粉的质量

C:滤渣N中一定没有单质镁

D:滤液M中至少含有两种金属阳离子

上一题 下一题 0.0难度 选择题 更新时间:2012-02-06 03:38:18

答案(点此获取答案解析)

B

同类题4

请先阅读下面短文,掌握其大意,然后从各小题所给的A、B、C、D四个选项中选出可以填入相应空白处的最佳选项。

    When I was a junior high school student in 1980, God gave me a gift, and it was happiness.

    One weekend, I went to visit my grandparents in the countryside. On my way home a car ran over me and broke off my1because of its high speed.

    Several days later when I woke up at the hospital, I realized(意识) I had to spend the rest of my life2arms. How sad I felt at that time! I was full of fears.3slowly I knew I had to face the fact and got over it. I couldn't get my arms back even though I4 every day.

    5, it's easier said than done.6took me nearly half a year to get out of the sadness completely. I got so much from my past story. From then on, I could treat(对待)my life with a7mind. But in our daily life, I often see my classmates8about little things: They get a bad grade on a test; their bus comes9; they don't have a mobile phone but10do, and so on. But I only11life. I was lucky to realize from an accident that it is a waste(浪费) of our life to focus on(集中注意力)12you have lost. We13always think of what we have. So why are so many people unhappy? Someone may say, “My whole life would improve14I have a new car.” But when you get the car what happens? For a whole week you are walking on air. Then you go right back to being unhappy.

    Happiness depends on what we have! It's in our heart. It's a state of mind, even though you own the whole world, you may still feel15. Happiness comes from mastering the art of appreciating(感激) and taking pleasure in what you really have.