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？

These days, publishers in Ramistan of glossy Western-style magazines rarely need to worry about interference from the government — the magazines’ content promotes consumption, and convincing Ramistan’s emerging middle class to spend their money is a key component of domestic policy. 想问选项A的and convincing是修饰谁的呢？修饰content的话为什么可以在前面加and？ 选项C为什么语法不正确呢？

plums are 75% water. prunes are 15% water. how much water must be evaporated for x kg of prunes? 这是我今天考场上的题，好像做错了。我乱选了（85x/15） 其他选项有各种 25x/85，15x/75什么的。应该怎么做？

一辆车，车轮上有一点离圆心 d cm，车子前进 D cm，问该点距离/车子前进的距离？ 1. d等于一个值 2. D等于一个值

Shoppers at Retailer R who purchased substitute items from other manufacturers on DayI paid a total amount that was approximately 78 of the total shoppers would have paid had each of them been able to purchase ProductXon Day 1. “was 和 would have paid ”都在一个从句里，怎末会有两个谓语动词？“had each of them been able to...”这部分是跟谁啊？看不懂

On his drive to work, Leo listens to one of three radio stations, A, B, or C. He first turns to A. If A is playing a song he likes, he listens to it; if not, he turns to B. If B is playing a song he likes, he listens to it; if not, he turns to C. If C is playing a song he likes, he listens to it; if not, he turns off the radio. For each station, the probability is 0.30 that at any given moment the station is playing a song Leo likes. On his drive to work, what is the probability that Leo will hear a song he likes? 这个题目的0.3为什末代指在A station 播放到了自己喜欢的？不太理解0.3到底指的是甚麽

提问叶老师，这个题我不太理解为什么appear要用单数？ D选项，what 指什么？from what 这个倒装正常语序应该怎么写？

等腰直角三角形的周长为：16+16√2 ；问斜边的长度 等腰直角三角形的非直角边一样长：那设为x 所以斜边就为（根据勾股定理）x√2 所以周长：x+x+√2 x=16+16√2 2x+√2 x=16+16√2 X=8√2 斜边就等于：16 问题：X=8√2 是怎么算出来的？

为什么算到这一步(3^2-2^2)(3^2+2^2)(3^4+2^4)就能直接算答案了（答案:5x13x97），难道有4次方的地方不继续化简吗？我怎么知道要把公式简化到哪一步？

老师好 我这道题的方法就是解二次方程，只有唯一正解才能证明是充分的。（我发现很多应用题都是这样）但是我发现解二次方程很浪费时间，考试的时候可能没那么充分的时间，怎么办呢？这道题还有更好的方法吗？谢谢老师