问题 选择题

下列实验方案或实验结论正确的是(  )

A.按溶解、过滤、蒸发的操作顺序从CuSO4和少量Fe粉的混合物中分离CuSO4

B.向鸡蛋清溶液中加入饱和(NH42SO4溶液,有白色沉淀产生,说明蛋白质发生了变性

C.向某烧碱溶液中滴加少量的稀盐酸,无气泡冒出,说明该氢氧化钠溶液一定没有变质

D.利用酚酞试液及溶液间的相互作用,可将Na2CO3、HCl、NaCl、NaOH四种溶液区分开来

答案

A、铁的金属活动性比铜强,溶解于水后,铁能与硫酸铜溶液发生置换反应生成硫酸亚铁和铜,则按溶解、过滤、蒸发的操作顺序不能从CuSO4和少量Fe粉的混合物中分离CuSO4,故实验方案或实验结论错误.

B、向鸡蛋清中加入饱和(NH42SO4溶液,可以观察到的现象为析出沉淀,说明饱和硫酸铵溶液可使蛋白质的溶解性变小,此过程叫做蛋白质的“盐析”,而不是变性,故实验方案或实验结论错误.

C、向某烧碱溶液中滴加少量的稀盐酸,无气泡冒出,盐酸会先和氢氧化钠反应,不能说明氢氧化钠溶液一定没有变质;故实验方案或实验结论错误.

D、Na2CO3、NaOH溶液显碱性,能使酚酞溶液变红;HCl、NaCl分别显酸性、中性,不能使酚酞溶液变红;盐酸能和碳酸钠反应生成二氧化碳气体;故分别滴加酚酞溶液,变红的是Na2CO3、NaOH溶液,不变色的是HCl、NaCl溶液,再将不变色的两种溶液分别滴加带变红色的两种溶液中,有气泡产生的是红色溶液、无色溶液分别是碳酸钠溶液、盐酸,无气泡产生的是红色溶液、无色溶液分别是氢氧化钠溶液、氯化钠溶液;故实验方案或实验结论正确.

故选D.

单项选择题
阅读理解

     She is a cute,  quiet girl. As a daughter,  she has no secrets from her mother,  who is very pleased with her. But recently she has become somewhat mysterious,  and not so open as before. She has a diary that

she keeps under lock and key. Her mother cannot help worrying about her: what if she falls in love, which

is too early for a girl of her age.After all she is reaching the "dangerous stage".These thoughts have caused

trouble in the mother's mind.

     One weekend the girl came to tell her mother that she was going to the cinema with her schoolmate

and would return late. This was the first time her mother agreed,  and she couldn't help worrying because

her daughter had never been away at night before. The mother waited till nine and her uneasiness got the

upper hand over her. She decided to go out to meet her daughter. Just at that moment the noise of a car

pulling up drew her to the window and-there was her daughter,  waving goodbye to a boy. Her heart

missed a beat. When the girl came in,  the mother was watching TV,  pretending nothing had happened. "Mum I'm back." "Yeah." "Sorry to be late. Still sitting up?" "Yes,  Oh,  that…Who's that boy?" The

daughter was stunned for a moment. "Ah. It's my monitor. He gave me a lift on his way home. Mum,  

I'm going to bed." "All right. Go to sleep early."

    Next morning when the mother went to the daughter's room to do some tidying,  she found her diary left at her pillow. After a few minutes' hesitation she eventually opened it to the entry of the night before. It read: Mum,  it's love that made you ask,  but it would show your understanding of me if you hadn't.

Holding the diary,  the mother fell into thought.

1.Which is the correct order according to the story?

a. She took a lift back in her monitor's car.

b. She went to see a film with her classmate.

c. She wrote in her diary to her mother.

d. Her mother pretended to watch TV.

e. Her mother worried about her daughter's returning late.

A.b,  e,  a,  d,  c  

B.e,  b,  a,  d,  c

C.b,  a,  e,  d,  c  

D.b,  e,  a,  c,  d

2.Which of the following is TRUE according to the story?

A.The girl knew her mother would ask her the question about the boy.

B.What the daughter did recently had worried her mother.

C.The mother was eager to read her daughter's diary the next day.

D.The girl's diary was always unlocked.

3.The main purpose of this article is to show that parents should________.

A.care about what their children really think and feel

B.not give much freedom to their children

C.talk with their children about their early love

D.keep silent about their children's privacy(隐私)

4.Which can be the best title for this story?

A.Mother's True Love

B.Early Love Between Students

C.To Ask or Not To Ask

D.Dangerous Age