When people engage in activities that help others, their brain releases endorphins, the brain’s natural opiates, which induce in people a feeling of well-being. It has been suggested that regular release of endorphins increases people’s longevity. And a statistic on adults who regularly engage in volunteer work helping others shows that they live longer, on average, than adults who do not volunteer. However, that statistic would be what we would expect even if volunteering does not boost longevity, because___________ Which of the following most logically completes the argument? A In the communities studied, women were much more likely to do regular volunteer work than men were, and women tend to live longer than men do B The number of young adults who do regular volunteer work is on the increase C The feelings of well-being induced by endorphins can, at least for a time, mask the symptoms of various conditions and diseases, provided the symptoms are mild D It is rare for a person to keep up a regular schedule of volunteer work throughout his or her life E Some people find that keeping a commitment to do regular volunteer work becomes a source of stress in their lives 错选了C，答案给的A。A说女士比男士更可能做志愿活动，女士比男士活得长。这不是支持原文了么？可以题目不是应该驳斥吗？

有24个brand，对每个brand的四个方面进行评估，这四个方面是ABCD，评估结果有四种，excellent，good，not good，bad，至少有几个brand的两个方面either excellent or good？ （1）至少有10个brand的两个方面是excellent （2）至少有12个brand的三个方面是good

a/c是否小于1？ （1） a/（c-1）小于1 （2） （a-1）/c小于1

切线与圆

PS：总共66个学生，有18个是business major，24个是新生，还有36个什么也不是，我忘了最后是问，仅仅是新生不是business major 的还是仅仅是business major不是新生的？ 构筑答案：好像答案不是12 就是16.。。 解析： 18和24代表的韦恩图圈圈有重合，36代表的是自己单独的圈圈。 Total =66； 36个学生不在Business和Fresh 范畴里面，所以F+B=30; F 和B的共有学生=12， 是B不是F=6； 是F不是B=12。

PS：挺简单的，就是一个数轴吧-5到15都涂黑了，然后问哪个式子能代表？ |x-5|<10 这个不等式怎么解来着？忘了。。。变号问题

PS：讲一个租赁汽车的公司每一次购买会购买5辆新车，每次卖掉会卖掉3辆旧车，今年新增了14辆车，把每次买和每次卖都算做一次交易，问今年最少做了几次交易？

If it took Carol 1/2 hour to cycle from his house to the library yesterday, was the distance that he cycled greater then 6 miles? ( 1mile=5,280feet) (1) The average speed at which Carlos cycled from his house to the library yesterday was greater than 16 feet per second. (2) The average speed at which Carlos cycled from his house to the library yesterday was less than 18 feet per second

Of the 12 temporary employees in a certain company, 4 will be hired as permanent employees. If 5 of the 12 temporary employees are women, how many of the possible groups of 4 employees consist of 3 women and one man? A. 22 B. 35 C. 56 D. 70 E. 105

if x is positive, is x >3 1. (x-1)^2 >4 2. (x-2)^2 >9

if the average of the consecutive even integers a,b, and c is less than 13a, which of the following best describes the value of a? 答案： a is positive 为什么呢？