根据短文内容，在短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。
There is an English saying:“71._________.” 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. _________.
Tests were carried out to study the effects of laughter on the body. People watched funny films while doctors checked their hearts, blood pressure, breathing and muscles. It was found that laughter has similar effects to
