阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式上。 The desire to be physically near others is human nature. We humans

阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式上。
The desire to be physically near others is human nature. We humans are social creatures. Many studies have shown that hunter-gatherers formed “bands” as they found___41___more efficient to find enough food for ___42___ （ survive)through joint efforts. They also found strength in numbers. When___43___( work)as a group, they could deal with threats more___44___ ( effective).
Today, having physical contact with other people and enjoying the company of others can release all sorts of chemicals in the brain and body, ___45___ essentially give us feelings of happiness and even love. This is___46___it's not just the athletes or the musicians that give us the sense of pleasure when we go to a concert or a football match. Being with a lot of other people ___47___ ( add)to the happiness. After events like this, people say they feel more___48___ ( bond)to one another and that they feel part of something whole.
In these complex___49___ ( society)we have developed,we head one another to get by.In hunter-gatherer days, one person or family may have been responsible for finding food, cooking it,building a home and making clothes.Now we rely heavily____50____other people from all over the world, with their own sets of knowledge and skills, to carry out different functions.
【答案】41. it    42. survival/surviving    
43. working    
44. effectively    
45. which    46. why    
47. adds    48. bonded    
49. societies    
50. on/upon
【解析】
本文是说明文。渴望在身体上接近别人是人的天性。人类是社会生物，需要依靠彼此生存。本文介绍了从古代到现代人际之间的依附关系。
【41题详解】
考查代词。句意：许多研究表明，狩猎——采集者形成了“一帮人”，因为他们发现通过共同努力找到足够的食物来生存更有效。分析句子可知，此处用it作宾语，真正的宾语是不定式短语to find enough food …，故填it。