问题 选择题

下列判断正确的是( )

A.如图①所示用湿润的pH试纸测定稀盐酸的酸碱度,会使pH偏小

B.实验室用NH4Cl和Ca(OH)2的固体混合物加热制氨气,选用图②装置

C.如图③所示配制50g 20%的蔗糖溶液,会使溶质质量分数偏小

D.图④实验可探究出燃烧的条件之一是需要氧气

答案

答案:B

题目分析:A、用湿润的pH试纸测定稀盐酸的酸碱度,会使pH偏大,故A错误;B、氯化铵和氢怕羞化钙均为固体,需要加热,故B正确;C、俯视量取的水比实际需要的水不,会使溶质的质量分数偏大,故C错误;D、该实验探究的是物质燃烧时温度需要达到可燃物的着火点,故D错误;答案为B。

单项选择题
阅读理解

A young woman carrying a three-year-old child got on a bus. The conductor hurried to give her a warm welcome and then kindly asked the other passengers to make more room for the woman and her child. On seeing this, people began to talk. "You know this conductor used to be very rude. Now suddenly he has changed his bad behavior , "said a middle-aged man.

"Yes, he should be praised and we must write a letter to the company," said a second passenger. "That's right," another lady said, "I wish a newspaper reporter were here so that more people could learn from this conductor. "

Just then a gentleman who looked like a teacher turned to the conductor and said , "Excuse me, but can I know your name, please? Your excellent service must be praised..."

Before he could open his mouth, the three-year-old child sitting on the young woman's lap interrupted, "I know his name. I call him Dad."

56. One passenger suggested writing a letter to the com­pany to ______    .

A. make a demand for more buses         B. thank the conductor for his good service

C. criticize the conductor for his rude behavior

D. invite a newspaper reporter to write about the conductor

57. What was the gentleman?

A. A teacher.                 B. A newspaper reporter.

C. Not known from the story.    D. The conductor's friend from his company.

58. The word "him" in the last paragraph refers to _______.

A. the gentleman    B. the conductor     C. the middle-aged man     D. the three-year-old child

59. It is clear from the story that the conductor _______.

A. has changed his attitude towards his work     B. has now been kind and polite to all passengers

C. has not changed his rude behavior to passen­gers

D. has now been kind and polite to women with children