13．There is an English saying，"（71）F"Until recently，few people took the saying seriously．Now however，doctors have begun to look into laughter and the effects it has on the human body．（72）G Tests were carried out to study the effects of laughter on the body．People watched funny films while doctors checked their heart，blood pressure，breathing and muscles．It was found that laughter has similar effects to physical exercise．（73）D If laughter exercises the body，it must be beneficial．
Other tests have shown that laughter appears to be able to reduce the effect of pain on the body．In one experiment doctors produced pain in groups of students who listened to different radio programs．The group that tolerated the pain for the longest time was the group which listened to a funny program．（74）C
（75）BThey have found that even if their patients do not really feel like laughing，making them smile is enough to produce beneficial effects similar to those caused by laughter．
A．Laughter can surely last one's life．
B．As a result of these discoveries，some doctors in the United States now hold laughter clinics，in which they help to improve their patients'condition by encouraging them to laugh．
C．The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemical in the brain which diminishes both stress and pain．
D．It increases blood pressure，makes the heart beat quicker and makes people breathe deeper； it also works several groups of muscles in the face，the stomach，and even the feet．
E．They have proved that laughter can really cure any disease if people keep a good state of mind．
F．Laughter is the best medicine．
G．They have found that laughter really can improve people's health．
分析 本文属于说明文阅读，作者通过这篇文章主要向我们描述了笑容对身体的影响，笑确实能改善人们的健康．
解答 71．F．推理判断题．从前面的句子：have begun to look into laughter and the effects it has on the human body医生开始研究笑以及对人类身体的影响，可知这句谚语跟笑有关．故选F．
72．G．推理判断题．从前面的句子：doctors have begun to look into laughter and the effects it has on the human body．可知笑可以改善人们的健康．故选G．
73．D．推理判断题．从前面的句子：It was found that laughter has similar effects to physical exercise．可知笑可知增加血压，心跳和呼吸加快．故选D．
74．C．推理判断题．从前面的句子：The group that tolerated（忍耐） the pain for the longest time was the group which listened to a funny program．可知笑可以减少疼痛的原因是会产生化学物质．故选C．
75．B．推理判断题．从后面的句子：They have found that even if their patients do not really feel like laughing 可知医生开笑声诊所帮助改善他们的状况．故选B．
点评 七选五阅读是完成性阅读，和完形填空很类似，不同的是一个选词，一个选句子．解题时，要注意上下文语境，充分考虑信息词（选项中和空格前后句子中相同或相近的词），选出最符合语境的句子
