问题 问答题

将6.9碳酸钾放入50g水中完全溶解后,加入80g硝酸钡溶液,恰好完全反应.计算:过滤后,所得滤液的溶质质量分数.(计算结果精确到0.1)

答案

生成沉淀的质量为x,生成硝酸钾的质量为y.

K2CO3+Ba(NO32=BaCO3↓+2KNO3

138              197     202

6.9g              x       y

138
6.9g
=
197
x
=
202
y

x=9.85g  y=10.1g

所得滤液的溶质质量分数为

10.1g
6.9g+50g+80g-9.85g
×100%≈7.9%

答:所得滤液的质量分数为7.9%.

阅读理解

My newly-rented small apartment was far away from the centre of London and it was becoming essential for me to find a job, so finally I spent a whole morning getting to town and putting my name down to be considered by London Transport for a job on the underground. They were looking for guards, not drivers. This suited me. I couldn’t drive a car but thought that I could probably guard a train, and perhaps continue to write my poems between stations. The writers Keats and Chekhov had been doctors. T.S. Eliot had worked in a bank and Wallace Stevens for an insurance company. I’d be a subway guard. I could see myself being cheerful, useful, a good man in a crisis. Obviously I’d be overqualified but I was willing to forget about that in return for a steady income and travel privileges — those being particularly welcome to someone living a long way from the city centre.

The next day I sat down, with almost a hundred other candidates, for the intelligence test. I must have done all right because after about half an hour’s wait I was sent into another room for a psychological test. This time there were only about fifty candidates. The interviewer sat at a desk. Candidates were signaled forward to occupy the seat opposite him when the previous occupant had been dismissed, after a greater or shorter time. Obviously the long interviews were the more successful ones. Some of the interviews were as short as five minutes. Mine was the only one that lasted a minute and a half.

I can remember the questions now: “Why did you leave your last job?” “Why did you leave your job before that?” “And the one before that?” I can’t recall my answers, except that they were short at first and grew progressively shorter. His closing statement, I thought, revealed (揭示) a lack of sensitivity which helped to explain why as a psychologist, he had risen no higher than the underground railway. “You’ve failed the psychological test and we are unable to offer you a position.”

Failing to get that job was my low point. Or so I thought, believing that the work was easy. Actually, such jobs — being a postman is another one I still desire — demand exactly the sort of elementary yet responsible awareness that the habitual dreamer is least qualified to give. But I was still far short of full self-understanding. I was also short of cash.

小题1:The writer applied for the job chiefly because _________.

A.he wanted to work in the centre of London

B.he could no longer afford to live without one

C.he was not interested in any other available job

D.he had received some suitable training小题2:The writer thought he was overqualified for the job because _________.

A.he often traveled underground

B.he had written many poems

C.he could deal with difficult situations

D.he had worked in a company小题3:The length of his interview meant that _________.

A.he was not going to be offered the job

B.he had not done well in the intelligence test

C.he did not like the interviewer at all

D.he had little work experience to talk about小题4:What does the writer realize now that he did not realize then?

A.How unpleasant ordinary jobs can be.

B.How difficult it is to be a poet.

C.How unsuitable he was for the job.

D.How badly he did in the interview.小题5:What’s the writer’s opinion of the psychologist?

A.He was very aggressive.

B.He was unhappy with his job.

C.He was quite inefficient.

D.He was rather unsympathetic.

单项选择题