问题 解答题

下面是一个健康人的血浆、原尿和尿液样品中主要物质的浓度比较,据此表回答:

物质样品A(g/100mL)样品B(g/100mL)样品C(g/100mL)
葡萄糖0.100.000.10
无机盐0.721.100.72
蛋白质8.000.000.03
尿素0.032.00.03
90.096.0098.00
样品A是______,原因是______

样品B是______,原因是______

样品C是______,原因是______.

答案

由上表可知:血浆与原尿的最主要区别是原尿与尿中不含大分子的蛋白质,尿与原尿、血浆的区别是不含有葡萄糖,根据以上可判断出样品A是血浆,样品B是尿液,样品C是原尿.

当血液(内含血浆和血细胞)流经肾小球时,除血液中的血细胞和大分子的蛋白质外,其他成分都可以滤过到肾小囊腔内形成原尿.因此,原尿与血浆相比,原尿中不含有大分子的蛋白质,而血浆中含有大分子蛋白质.样品A中的蛋白质含量为8.00g/mL,故样品A是血浆.

样品A尿与样品B血浆相比,由于肾小管的重吸收作用,把大部分水分、部分无机盐,少量小分子蛋白质,全部葡萄糖重吸收回血液,而尿素并没有被重吸收,水少了,溶质不变,因此,尿液中尿素的含量最高,并且不含蛋白质和葡萄糖.样品B不含蛋白质和葡萄糖,尿素的含量最高,故样品B是尿液.

当原尿流经肾小管时,由于肾小管的重吸收作用,把大部分水、部分无机盐,少量小分子蛋白质,全部葡萄糖重新吸收回血液后,因此,原尿中有葡萄糖而尿液中无葡萄糖,样品C中含有葡萄糖,含少量蛋白质,故样品C是原尿.

故答案为:血浆;样品A中的蛋白质含量为8.00g/mL;

尿液;样品B不含蛋白质和葡萄糖,尿素的含量最高;

原尿;样品C含少量蛋白质,含有葡萄糖.

阅读理解

阅读理解。

      Many young people want to be pop stars. They think it would be a wonderful life. In fact most pop

stars have very hard lives. They spend much of their time on tour, and though this can be fun, it can also

be exhausting(疲倦).

     This is a typical day in the life of pop star on tour.

Novermber 26

     5:00 A.M. Woke up in hotel room. Packed bags. Met manager in hotel lobby. Took taxi to airoirt.

     6:00 Breakfast at airport. Discussed day's timetable with manager. Plane's departure delayed an hour

by fog.

     7:45 Finally boarded plane.

     8:30 Arrived and waited half an hour for luggage. Then gave interview to TV crew.

     9:45 Gave first radio interview of the day.

     10:15 Went from radio station to radio station giving interviews.

     12:00 P.M. Interview and lunch with stupid journalist who'd never heard of me.

     1:00 Had photo for newspaper.

     1:15 Went to theatre to check lighting. Met local producer and band-very poor.

     2:00 Rehearsed show. Band a little better.

     5:00 Back to hotel. Showed and tried to test but too worried about band.

     6:30 Back at theatre. Changed into costume for show.

     7:30 On stage at last. Gave performance. Band very bad but audience love me.

     10:00 Party after show. Met fans and more journalists.

     11:00 Fell into bed exhausted. Set alarm for the morning.

1. The main idea of the passage is ______.

A. lots of young people want to be pop stars

B. most pop stars have hard lives

C. pop stars have a wonderful life

D. pop stars have a lot of fun on tour

2. When did the pop star give interviews?

A. From 6:00 a.m. to 1:00 p.m..

B. From 7:45 a.m. to 10:15 p.m..

C. From 9:00 a.m. to 1:00 p.m..

D. From 8:30 a.m. to 10:15 p.m..

3. What was wrong with the performance?

A. The pop singer performed badly.

B. The audience didn't like the pop star.

C. The show didn't srart on time.

D. The band performed badly.

4. Why do pop star have hard lives?

A. Because lots of people want to be pop star.

B. Because they spend a lot of time touring.

C. Because touring isn't exhausting.

D. Because being a pop star is wouderful.

5. How long was the popular star's day?

A. 11 hours

B. 16 hours

C. 18 hours

D. 12 hours

单项选择题