问题 选择题

观察、分析实验现象,可以帮助我们理解科学的本质.下列现象描述与事实不相符 的是(  )

A.铁丝在氧气中剧烈燃烧,火星四射,生成黑色固体,放出大量的热

B.把燃着的木条放在盛满二氧化碳的集气瓶口,木条熄灭

C.硫酸铜溶液与氢氧化钠溶液混合,生成蓝色沉淀

D.加热氯化铵与氢氧化钠固体混合物,生成能使湿润蓝色石蕊试纸变红色的气体

答案

A、铁丝在氧气中剧烈燃烧,火星四射,放出大量的热,生成一种黑色固体,故选项说法正确.

B、二氧化碳不能燃烧,也不能支持燃烧,故把燃着的木条放在盛满二氧化碳的集气瓶口,木条熄灭;故选项说法正确.

C、硫酸铜溶液与氢氧化钠溶液混合,生成蓝色沉淀氢氧化铜;故选项说法正确.

D、铵盐与碱性物质反应放出氨气,加热氯化铵与氢氧化钠固体混合物有氨气生成,氨气遇水形成呈碱性的氨水,能使湿润的石蕊试纸变成蓝色;故选项说法错误.

故选D.

阅读理解

___小题1:Stephen: Last summer I went through a training program and became a literacy volunteer. When I began to discover what other people's lives were like because they could not read, I realized the true importance of reading.

___小题2:Susan: I'm a girl from England and has studied French for years. I'm here in Fudan University studying Chinese. I like China as it is full of mysteries. So I hope the voluntary work will help me to get in touch with Chinese people and get to know about China.Although my study is busy, I can be free at night and at the weekends.

__小题3:Tim: Since I myself have overcome a lot of difficulties in my life, I understand young people's problems and I know how to listen patiently to others and offer some advice. I'm working now in the daytime so I can only spend two to three hours a day at night to help others.

小题4:Lisa: I burst into tears when I saw those children in a TV programme. What a sight. They are only bone and skin left. What's worse, every day the children are dying because of lack of food.I realized how lucky I am with enough food and a good chance to get education. The summer vacation is coming and I hope I can do something for them.

A.As we know, the 2010 World Expo are held in Shanghai and many people from other countries come to visit China.The taxi drivers in Dongfeng Taxi Company think the way to show kindness is to be able to greet the foreigners in their languages. They need someone who can teach them languages and the best time is at night when they are not so busy.

B.Tom is so addicted to on-line games that he cannot concentrate on his study like before. Now he often misses school in order to play games, thus telling lies to his teachers and parents again and again. Though he realizes what he does is wrong, he just can't stop it. How badly he needs someone's help.

C.Mane, a 44-year-old single mother of three, has to walk two miles to the nearest supermarket twice a week because she doesn't know which bus to take. What's worse, since she does not know words, she can not write out a shopping list. Also, she can only recognize items by sight, so if the product has a different label, she will not recognize it as the product she wants.

D."Helping hand" organization will hold an event to help the starving children in Africa.The event starts in August and those taking part in will go without food for 30 hours. In this way, it is expected that money will be raised for the poor children.

单项选择题