问题 推断题

(5分)现有A、B、C、D、E、F、G、H八种物质,它们有如下所示关系:其中A是一种暗紫色固体,B、G都是黑色固体,D能使带火星的木条复燃,E是一种无色液体,H是一种能使澄清石灰水变浑浊的气体,在②的反应前后B的质量和化学性质都不改变。

请你根据上述信息,推断出下列物质并写出各物质的化学式:

A           、B            、D           、E            、H           

答案

A:KmnO4; B: MnO2; D:O2; E:H2O2; H:CO2。 

(其他合理答案均可) 

题目分析:由题意可知:D能使带火星的木条复燃,D是氧气;A是一种暗紫色固体,A是高锰酸钾;H是一种能使澄清石灰水变浑浊的气体,H是二氧化碳;在②的反应前后B的质量和化学性质都不改变,B是二氧化锰;G都是黑色固体,H是二氧化碳,G是碳;E是过氧化氢;F是水。

故有:A:KmnO4、B:MnO2、D:O2、E:H2O2、H:CO2

点评:推断物质的关键是寻找突破口,题中“D能使带火星的木条复燃,H是一种能使澄清石灰水变浑浊的气体”是解题的突破口。

化学式中的字母和数字都有着特定的含义,不能随意书写,同学们要牢记并理解其意义。

单项选择题
阅读理解

After Mom died, l began visiting Dad every morning before I went to work. He was frail and moved slowly, but he always had a glass of freshly squeezed orange juice on the kitchen table for me, along with an unsigned note reading," Drink your juice." Such a gesture, l knew, was as far as Dad had ever been able to go in expressing his love. In fact, l remember, as a kid I had questioned Mom "Why doesn't Dad love me?" Mom frowned, "Who said he doesn’t love you?" "Well, he never tells me, "I complained." He never tells me either," she said, smiling. " But look how hard he works to take care of us, to buy us food and clothes, and to pay for this house. That's how your father tells us he loves us. "

I nodded slowly. I understood in my head, but not in my heart. l still wanted my father to put his arms around me and tell me he loved me. Dad owned and operated a small scrap (片) metal business, and after school I often hung around while he worked. Dad handled scrap steel into a device that chopped it as cleanly as a butcher chops a rack of ribs. The machine looked like a giant pair of scissors, with blades thicker than my father's body. If he didn’t feed those terrifying blades just right, he risked serious injury. "Why don' t you hire someone to do that for you?" Mom asked Dad one night as she bent over him and rubbed his aching shoulders with a strong smelling liniment. "Why don’t you hire a cook?" Dad asked, giving her one of his rare smiles.

Many years later, during my first daily visit, after drinking the juice my father had squeezed for me. l walked over, hugged him and said, "I love you, Dad." From then on I did this every morning. My father never told me how he felt about my hugs, and there was never any expression on his face when I gave them.

小题1:What would be the best title for the passage?

A.My father never loved me

B.I just couldn't understand my father

C.My hard-working father

D.Silent fatherly love小题2:The author’s father always prepared a glass of freshly squeezed orange juice for him because____.

A.that was the author's favorite

B.that was a gesture of love

C.the author was always complaining

D.he was sure the author would be thirsty小题3:The author’s father didn’t hire a helper because________.              .

A.he wanted to save money

B.his job required high skills

C.his job was too dangerous

D.he was not good at communicating with others小题4:We may infer from the passage that _______.

A.the author's father lacked a sense of humor

B.the author's-father didn't love him very much

C.the author quite understood his father as time went on

D.the author's father was too strict with him