6.verception of fatness：对于肥胖的感知。
7.The investigators say their findings can help explain why Americans have become fatter in recent years—each person who became obese was likely to drag along some friends：调查人员声称他们的发现可以帮助解释近年来美国人变得越来越胖的原因：每个发胖的人都可能带动朋友一起变胖。
8.contagion：传染，传染病。
9.edge toward：向……缓慢或逐渐地前进。
练习：
1. Who had the greatest influence on people who became obese？
A) Their friends.
B) Their neighbours.
C) Their family members.
D) Their colleagues.
2. Which of the following statement about a friends influence is false according to the report？
A) Friends had more influence than family members on people who became obese.
B) Even ifthe friend lives far away， the influence still remained.
C) People were not likely to lose weight when they have skinny friends.
D) The greatest influence of all was between close mutual friends.
3. According to Dr. Nicholas A. Christakis， what is the explanation for friends being the
greatest influence？
A) Friends usually spend a lot of time together.
B) Friends share similar eating habits.
C) Friends are more important than family members.
D) Friends affected each others feelings of fatness.
4. Which factor of becoming obese is not mentioned in this report？
A) Social contact.
B) Genetic information.
C) Life style.
D) Environmental influences.
5. In what way is obesity contagious and epidemic？
A) Social networks let the obesity spread rapidly.
B) Individuals have genetically determined ranges of weights.
C) Obesity can easily spread from one to another without any physical contact.
D) Obesity can spread rapidly and extensively by infection and affecting many individuals in an area or a population at the same time.
参考答案：ACDCA