In the country of Veltria, the past two years' broad economic recession has included a business downturn in the clothing trade, where sales are down by about 7 percent as compared to two years ago. Clothing wholesalers have found, however, that the proportion of credit extended to retailers that was paid off on time fell sharply in the first year of the recession but returned to its prerecession level in the second year. Which of the following, if true, most helps to explain the change between the first and the second year of the recession in the proportion of credit not paid off on time? (A) The total amount of credit extended to retailers by clothing wholesalers increased between the first year of the recession and the second year. (B) Between the first and second years of the recession, clothing retailers in Veltria saw many of their costs, rent and utilities in particular, increase. (C) Of the considerable number of clothing retailers in Veltria who were having financial difficulties before the start of the recession, virtually all were forced to go out of business during its first year. (D) Clothing retailers in Veltria attempted to stimulate sales in the second year of the recession by discounting merchandise. (E) Relatively recession-proof segments of the clothing trade, such as work clothes, did not suffer any decrease in sales during the first year of the recession. 这道题错选了A。 思路如下： 题目问的是为什么在经济不好，衣服卖不动的情况下，第一年零售商还不上钱第二年就能还上了。讲的是零售商还钱的问题。 当时留下的是A,C,D 排除D是因为觉得，即使刺激销售量衣服打折也不能说明能还上钱。可能打折卖1块，纵使家当全卖了也不够。 排除C是因为觉得， 那些本身经济状况就很差的在第一年被淘汰掉以后，剩下的那些没说经济状况如何啊，如果也不咋地，第二年还是得淘汰啊。 A选项当时觉得，即使credit extended，对pay off on time也无太大用处，但最起码跟原文意思接近。所以选了A。

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求问此题的解题思路：已知整数0到k的乘积能被735整除。 问：k的最小值是多少？

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求问此题的解题方法：符合k，k+2，k+4三个数都是质数的set有多少个？（k>1) 答案有：0, 1，2，3，>3。请问May老师这种题型该怎么求解呀？谢谢！

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7/15寂静：所有员工都大于20岁. Of the 2000 employees, is the avg age at least 35? 1. 50% 员工是大于40岁 2. 25% 员工是大于65岁 这道题网上有C和E两种争论；我所不明白的点是：条件2中的25%是否包含在条件1的里面；我觉得答案应该是C。因为：35*2000=70000岁；（1）+（2）可得41*500+66*500+21*1000=74500＞70000.不知道我的思路是否正确。谢谢老师的答疑！

【请May老师回答】这题鸡精提供的答案是D 可是我觉得第二个条件不能得出呢 假设n三次方是x平方 除以n平方 是可以得到x/ n 平方 但是x/n 不一定是整数呀？