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问题 单项选择题

弯曲试验时，经机加工后的试样直径或多边形（）。

A.外接圆直径不小于25mm

B.内切圆直径不小于25mm

C.外接圆直径不大于25mm

D.内切圆直径不大于25mm

答案

参考答案：B

单项选择题

(B)


Tim Richter and his wife, Linda, had taught for over 30 years near Buffalo, New York—he in computers, she in special education. "Teaching means everything to us", Tim would say. In April 1998, he learned he would need a heart operation. It was the kind of news that leads to some serious thinking about life’s purpose.
Not long after the surgery, Tim saw a brochure describing Imagination Library, a program started by Doily Patron’s foundation (基金会) that mailed a book every month to children from birth to age five in the singer’s home town of Sevier, Tennessee. "I thought, maybe Linda and I could do something like this when we retire," Tim recalls. He placed the brochure on his desk, "as a reminder."
Five years later, now retired and with that brochure still on the desk, Tim clicked on imagination library. The program had been opened up to partners who could take advantage of book and postage discounts.
The quality of the books was of great concern to the Richters. Rather than sign up online, they went to Dollywood for a look-see. "We didn’t want to give the children rubbish," says Linda. The books-reviewed each year by teachers, literacy specialists and Dollywood board members-included classics such as Ezra Jack. Keats’s The Snowy Day and newer books like Anna Dewdney’s Llama series.
Satisfied, the couple set up the Richter Family Foundation and got to work. Since 2004, they have shipped more than 12,200 books to preschoolers in their area. Megan Williams, a mother of four, is more than appreciative "This program introduces us to books I’ve never heard of."
The Richters spend about $400 a month sending hooks to 200 children. "Some people sit there and wait to die," says Tim. "Others get as busy as they can in the time they have left.\

What led Tim to think seriously about the meaning of life

A. His health problem

B. His love for teaching
C. The influence of his wife
D. The news from the Web
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多项选择题

一般来说，建设项目的生态监测包括的内容应当有( )。

A．生态环境问题的概述

B．重要生态因素、生态监测的因子或指标体系的确定

C．监测点位、时段和频率，监测人员、监测设备和经费

D．监测结果的评价与报告，提出的应急与持续改进措施
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