问题 选择题

下列有关实验操作的叙述中,合理的是

A.把SO2通入紫色石蕊试液,可验证SO2的漂白性

B.中和滴定前,用待测液润洗锥形瓶

C.将10g CuSO4·5H2O溶解在90g水中配制10%的CuSO4溶液

D.配制一定物质的量浓度的溶液,定容时俯视容量瓶的刻度线,会使所配溶液浓度偏高

答案

答案:D

A.把SO2通入紫色石蕊试液,可验证SO2溶于水,水溶液为酸性;

B.中和滴定前,不能用待测液润洗锥形瓶,否则会造成测量结果偏大;

C.将10g CuSO4·5H2O溶解在90g水中配制的CuSO4溶液小于10%。

单项选择题
阅读理解

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."

1. 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

2. 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.

3. 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

4. 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