已知甲、乙、丙三个城市的经济效益指标．如表2—8所示。
表2-9
| 实际值 | ||||
| 单位 | 甲 | 乙 | 丙 | |
| 总资产贡献率 | % | 5.81 | 6.35 | 7.10 |
| 工业劳动生产率 | 元/人 | 41686.80 | 32.066.12 | 55525.30 |
总资产贡献率、工业劳动生产率的标准差为( )。
| A．0.529%；3258 | B．0.529%；9629 |
| C．1.55%；3258 | D．1.55%；9629 |
参考答案：
解析：[答案] B 总资产贡献率的标准差为： 工业劳动生产率的标准差为：
| 阅读理解。 | ||||||||||||||
| Everyone has a dream job and we all hope our dreams can come true. Mr Black works as a reporter at a TV station. He wants to know what jobs teenagers are going to do when they grow up. He went to the Evergreen School to do a survey (调查) last Friday. Mr Black asked the students to discuss with each other and then fill in the form with a pen. He told them to tell the truth. Mr Black thought most students would be teachers. The teacher is one of the best professions (职业) in the world. Maybe some students would be scientists. Rich knowledge would help them. A few students would be soldiers (士兵) because they could keep our country beautiful and peaceful. Teachers helped Mr Black before school was over. They gave out one thousand eight hundred papers to the students. When the survey's result came out, Mr Black and the teachers were surprised. Please look at the results.
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| 1. From the first paragraph, we know this passage may talk about __________. | ||||||||||||||
| A. teenagers' dream jobs B. Mr Black and his job C. how dreams come true D. how to make a survey | ||||||||||||||
| 2. What does Mr Black do? | ||||||||||||||
| A. He is a teacher. B. He is a reporter. C. He is a soldier. D. He is an actor. | ||||||||||||||
| 3. Why did Mr Black do a survey last Friday? | ||||||||||||||
| A. Because he wanted to find a job for himself. B. Because he wanted to know about students' dream jobs. C. Because he was always interested in doing a survey. D. Because he wanted to know how much money teenagers got a week. | ||||||||||||||
| 4. Which of the following did most students choose? | ||||||||||||||
| A. Actor. B. Sports player. C. Teacher. D. Scientist. | ||||||||||||||
| 5. How many teenagers want to be teachers in the future? | ||||||||||||||
| A. 90. B. 360. C. 900. D. 1800. |