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问题 填空题

判断下面两种量成什么比例．

（1）铺地面积一定，方砖的面积和用砖的块数．______

（2）如果y=7x，则x和y．______

（3）互为倒数的两个数．______

（4）圆的面积和它的半径．______．

答案

（1）因为每块方砖的面积×方砖的块数=铺地的面积（一定），符合反比例的意义，所以铺地的面积一定，每块方砖的面积和方砖的块数成反比例；

（2）因为y=7x，所以y：x=7（一定），是比值一定，x和y成正比例．

（3）互为倒数的两个数，它们的积等于1，所以互为倒数的两个数成反比例．

（4）因为S÷r=πr，r变化，πr就变化，所以圆的面积和它的半径不成比例；

故答案为：反比例，正比例，反比例，不成比例．

多项选择题

甲公司欠乙公司30万元，一直无力偿付，现丙公司欠甲公司20万元，已到期，但甲公司明示放弃对丙的债权。对甲公司的这一行为，乙公司可以采取以下哪些措施？

A．行使代位权，要求丙偿还20万元

B．请求人民法院撤销甲方弃债权的行为

C．乙行使权利的必要费用可向甲方主张

D．乙方应在知道或应当知道甲放弃债权2年内行使权利
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单项选择题

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 can we learn from Tim’s words in the last paragraph

A. He needs more money to help the children.
B. He wonders why some people are so busy.
C. He tries to save those waiting to die.
D. He considers his efforts worthwhile.
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