题干

下列化学知识中推理归纳分析正确的是(   )

A:氧化物中都含有氧元素,所以含有氧元素化合物都氧化物

B:蔗糖在热水中的溶解速度更快,由此推断在受热情况下分子运动速率加快

C:单质只含一种元素,所以含一种元素的物质一定是单质

D:离子是带电的原子或原子团,所以带电的微粒一定是离子

上一题 下一题 0.0难度 选择题 更新时间:2020-02-08 09:05:07

答案(点此获取答案解析)

B

同类题2

    Jim, a successful businessman, told the experience of his childhood.
    When he was 12, his parents 1. He was alone and didn’t get on well with others. People always laughed 2 him. No one showed kindness (友善) to him. His only friend was a dog named Tige.
    One day as he walked down the street, a young lady was walking in front of him. Suddenly one of her bags dropped from her arms. As she stopped3, she dropped other bags. He came to help her.“Thank you, dear! You are a nice little boy!”She said kindly, smiling.
A special feeling came to him. These were 4 kind words he had ever heard. He watched her 5she went far away, and he whistled(吹口哨)to his dog and went directly to the river nearby.
    “Thank you, dear! You are a nice little boy!”he repeated the woman's words. Then in a low    6 he said to his dog,“You are a nice little dog!”Tige raised 7 ears as if(似乎)it understood.
    “Uh! Even a dog likes it!”he said,“Well, Tige, I won't say unkind words to you any more.”Tige waved its tail happily.
    The boy thought and thought. Finally he looked at himself in the river. He saw 8 but a dirty boy. He washed his face9. Again he looked. He saw a clean nice boy. He was amazed (震惊). From then on, he had a new life.
    After telling this, the businessman stopped for a while, and then he said,“Ladies and gentlemen, this is the very place where that kind woman planted in me the first seed (种子) of kindness. All of us should learn about kindness. 10a great power it has!” If you show kindness to others, you will be an able man.