问题 选择题

不用试剂只用试管和滴管不能鉴别下列无色溶液的是(  )

A.碳酸钠溶液和稀硫酸

B.氯化铝溶液和氢氧化钠溶液

C.四羟基合铝酸钠溶液和稀盐酸

D.氯化钡溶液和碳酸钠溶液

答案

答案:D

由于碳酸钠和酸反应是分步进行的,因此将硫酸逐滴滴入碳酸钠中开始得不到CO2气体。但将碳酸钠滴入硫酸中,则开始就得到CO2气体;氢氧化铝是两性氢氧化物,因此B中氯化铝滴入氢氧化钠中开始得不到白色沉淀。但氢氧化钠溶液滴入氯化铝中名考生可以得到白色沉淀;同样四羟基合铝酸钠溶液滴入盐酸中,开始得不到白色沉淀。但盐酸滴入四羟基合铝酸钠溶液中,开始可以得到白色沉淀;选项D中二者无论怎么样的滴加顺序,都是产生白色沉淀,因此答案选D。

阅读理解

Many students in China are learning English. Some of these students are small children. Others are teenagers(青少年). Many are adults(成年人). Some study at school, others learn by themselves. A few learn English language over the radio, on TV, or in the films. One must work hard to learn another language.

Why do all these people want to learn English? It is difficult to answer that question. Many boys and girls learn English at school because it is one of their subjects. They study their own(自己的) language and maths and English. Some people learn English because it is useful for their work. Many people often learn English for their higher studies, because at college or university(大学) some of their books are in English. Other people learn English because they want to read newspapers and magazines in English.

小题1:根据Others are teenagers(青少年). Many are adults(成年人).描述,可知选C。

小题2:根据短文第一段描述,可知孩子,年轻人和成人都在学英语。故选C。

小题3:根据短文第二段描述,可知每个人学英语都有不同的原因,故选D。

小题4:联系上文可知本文描述的是中国人学英语,故他们自己的语言是汉语,选A。

小题5:by表示通过某种方式,通过自己学习英语,及自学英语,故选B。

小题6:Are there many adults learning English in China?

A.No, they aren’t.

B.No, they are.

C.Yes, there are.

D.Yes, there aren’t.小题7:________learn English.

A.Only teenagers.

B.Only adults.

C.Small children, teenagers and adults.

D.Only small children.小题8:Which of the following is true?

A. Most people learn English over the radio.

B. All the people learn English at school.

C. Students only learn their own language at school.

D. Different people have different reasons for learning English.小题9:“Their own language” means_____________.

A.Chinese

B.English

C.French

D.Japanese小题10:What’s the Chinese meaning of “learn by themselves”?\

A.和他们一起学习

B.自学

C.向他们学习

D.通过学习

填空题