1 the best recruiting agents

Seneca and Beaumarchais would have agreed that

1. 
   there is nothing in life that cannot be seen as funny in some way
   
2. 
   it is necessary to cry if something isn't at all humorous
   
3. 
   the best way to deal with unpleasant events is to laugh at them
   
4. 
   everything in life could be seen as either humorous or tragic
   
5. 
   you should be careful about whether a particular situation requires you to laugh or to cry
   

2. 
   Laughing and crying are similar in that
   

1. 
   each action provides the body with stimulation
   
2. 
   they both leave people somewhat relaxed
   
3. 
   they are both the result of excessive hormones
   
4. 
   many people cannot distinguish the difference between them
   
5. 
   they are produced by the same stimuli
   

3. 
   It is difficult to define humour and identify the causes of laughter because
   

1. 
   people find it difficult to look at comedy seriously
   
2. 
   most people are much more concerned with tragedy
   
3. 
   people get nervous when being studied and so cannot laugh
   
4. 
   the physical responses to humour are already known
   
5. 
   there is no easy way to study emotions scientifically
   

98 BOUNCING BALLS AND BEATING HEARTS
Over 200 years ago, the British chemist Joseph Priestley received an intriguing bouncy ball from an American friend. It was made of a material he had not seen before. Priestley noticed that it could rub away pencil marks, and so he named the material rubber. Not only has the name stuck, but since then rubber has become so important to modern society that it is hard to imagine life without it. The flexibility, elasticity, and durability of natural and synthetic rubbers have made them the choice materials for products that cushion shocks, soften blows, dampen vibrations, transmit power, and perform in many other ways. Tires, automotive components, electrical insulation, conveyor belts, theatre seats, building materials, footwear, elastic bands, tennis balls, surgical gloves, artificial hearts, and refrigerator linings - these are only a sampling of the huge and growing list of products that are completely or partly made of rubber.

1.