Women are friendly. But men are more competitive. Why? Researchers have found it's all down to the hormone oxytocin (荷尔蒙催生素). Although known as the love hormone, it affects the sexes differently.
"Women tend to be social in their behavior. They often share with others. But men lend to be competitive. They are trying to improve their social status," said Professor Ryan.
Generally, people believe that the hormone oxytocin is let out in our body in various social situations and
our body creates a large amount of it during positive social interactions (互动) such as falling in love or giving birth.
But in a previous experiment Professor Ryan found that the hormone is also let out in our body during negative social interactions such as envy.
Further researches showed that in men the hormone oxytocin improves the ability to recognize competitive relationships, but in women it raises the ability to recognize friendship. Professor Ryan's recent experiment used 62 men and women aged 20 to 37. Half of the participants（参与者）received oxytocin. The other half received placebo (安慰剂).
After a week, the two groups switched with participants. They went through the same procedure with the other material.
Following each treatment, they were shown some video pictures with different social interactions. Then they were asked to analyze the relationships by answering some questions. The questions were about telling friendship from competition. And their answers should be based on gestures, body language and facial expressions.
The results indicated that, after treatment with oxytocin, men's ability to correctly recognize competitive relationships improved, but in women it was the ability to correctly recognize friendship that got better.
Professor Ryan thus concluded: "Our experiment proves that the hormone oxytocin can raise people's abilities to better distinguish different social interactions. And the behavior differences between men and women are caused by biological factors (因素) that are mainly hormonal."
47. What causes men and women to behave differently according to the text?
A. Placebo.                              B. Oxytocin.
C. The gesture.                     D. The social status.
48. What can we learn from Professor Ryan's previous experiment?
A. Oxytocin affects our behavior in a different way.
B. Our body lets out oxytocin when we are deep in love.
C. Our body produces oxytocin when we feel unhappy about others' success.
D. Oxytocin improves our abilities to understand people's behavior differences.
49. Why did Professor Ryan conduct the recent experiment?
A. To test the effect of oxytocin on the ability to recognize social interactions.
B. To know the differences between friendship and competition.
C. To know people's different abilities to answer questions.
D. To test people's understanding of body language.
50. The author develops the text by______.
A. explaining people's behaviors                  
B. describing his own experiences
C. distinguishing sexual differences      
D. discussing research experiments
【考点】考察科普知识类阅读
【文章大意】文章讲述了Professor Ryan调查实验，实验告诉我们荷尔蒙催生素能提高人们辨认不同的社会交往的能力；男女之间行为的差异是由主要是荷尔蒙的生物因素所引起的。
47. 【答案】 B
【试题解析】细节题。根据文章第一段1,2行Women are friendly. But men are more competitive. Why? Researchers have found it’s all down to the hormone oxytocin(荷尔蒙催生素)可知，男女之间行为表现的不同是由于荷尔蒙催生素水平的不一样导致的。故B正确。
48. 【答案】 A
【试题解析】推理题。根据文章第三段Generally, people believe that the hormone oxytocin is let out in our body in various social situations and和our body creates a large amount of it during positive social interactions (互动) such as falling in love or giving birth.第四段But in a previous experiment Professor Ryan found that the hormone is also let out in our body during negative social interactions such as envy在实验里Professor Ryan发现在消极的社会交往中，我们身体也释放出荷尔蒙，可知之前的实验告诉我们hormone oxytocin (荷尔蒙催生素)使用了另外一种形式来影响我们的行为。故A正确。
49. 【答案】 A
【试题解析】推理题。文章最后三行Professor Ryan thus concluded: "Our experiment proves that the hormone oxytocin can raise people's abilities to better distinguish different social interactions. And the behavior differences between men and women are caused by biological factors (因素) that are mainly hormonal."
可知，最近这次实验是想测试一下荷尔蒙催生素对辨认社交能力的效果，而结果证实了荷尔蒙催生素能提高人们的这种能力。
50. 【答案】 D
【试题解析】推理题。作者是通过讨论所做的不同的实验产生的不同的结果而展开，之前的实验结果和现在的实验结果的比对。产生新的结论。故D正确。
【长难句解析】
Further researches showed that in men the hormone oxytocin improves the ability to recognize competitive relationships, but in women it raises the ability to recognize friendship.
【翻译】进一步地研究显示在男性身上，荷尔蒙催生素能够提高辨认竞争性关系的能力，但是在女性身上，它能够提高辨认友谊的能力。
【分析】本句中的动词show后面有两个宾语从句in men the hormone oxytocin improves the ability to recognize competitive relationships, but in women it raises the ability to recognize friendship.使用了and连接。