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？

r/t=2? 条件1：点（r,t）在（0，y）和（x，0）这条直线上，x和y不记得了 条件2：点（r,t）过（0，4）和（3，6）

K P M是三个正整数，问KP+M是奇数吗？ 条件1：KM+P是奇数 条件2：PM+K是偶数

DS：x/a+y/b=1，求该直线与x轴的交点？ 条件1：b=3 条件2：a=b

PS：m,p都是正整数，p是质数。x2-mx+p=0这个方程的根是正数。求m-p的值？ 选项有1，2，4之类。

DS：有12个人给老师买礼物，每个人至少出一块钱，总共出的钱是否不少于30 条件1：有一半的人至少出3块钱 条件2：4个人出的钱至少是出钱最少的人出的钱的5倍

DS：定义F(n)=n/k的余数，问K>10？ 条件1：F(n+32)=6 条件2：F(n+42)=8

PS：一个国家telephone exchange numbers有七个digits，但前三个digits都是一样的数字，例都是932打头。问至少需要多少个数字(minimum required number)可以组成282000个telephone exchange numbers？ 选项是：三个2十几的数字和两个2百几的数字。

DS：a,b,c,d互不相等，(a-c)/(b-d)=a/b吗？ 条件1：a/b=c/d 条件2：(a+c)/(b+d)=a/b

PS：the value of （4^8 - 8^16）/（2^12 – 4^16）

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？