23、Some people say that laughter is the best medicine．Scientists arc studying laughter carefully and finding it really good for us．

What happen when we laugh? We use fifteen different muscles in our face，and laughing is good for our body．When we laugh，we breath quickly and exercise the face，shoulders and chest．Our blood pressure goes down，and our circulation gets better．Our heart beat is lower．Our brain makes a rural painkiller．

Every minute we laugh is the same as forty-five minutes relaxation．Many doctors around the world believe that laughter helps us get better when we are sick．

Of course，there are many kinds of laughters．Different people have different laughters．We may change the way we laugh in different situations，But everyone has his own way to laugh．How do you usually laugh?

1．Laughter is good for us because ________．

A．everybody thinks so                         B．doctors say so

C．scientists are studying                               D．everyone likes laughing

2．When we laugh，we exercise ________．

A．fifteen muscles of the face                     B．fifteen muscles of the chest

C．every place of our body                      D．fifteen organs of our body

3．Laughter makes a natural painkiller ________．

A．in our shoulders      B．in our heart           C．in our brain          D．in our blood

4．One minute laugh equals forty-five minutes ________．

A．exercise            B．rest                C．thinking             D．sports

5．According to the passage，________．

A．people laugh in the same way

B．one should learn different ways of laughing

C．we need to laugh forty-five minutes each day

D．everyone has his own way of laughing