英语翻译When you go to the doctor,you like to come away with a p

英语翻译When you go to the doctor,you like to come away with a prescription.It makes you feel better to know you will get some medicine.But the doctor knows that medicine is not always needed.Sometimes all a sick person needs is some reassurance that all will be well.In such cases the doctor may prescribe a placebo（安慰剂）.A placebo is a sugar pill,a harmless shot,or an empty capsule.Even though they have no medicine in them,these things seem to make people well.The patient thinks it is medicine and begins to get better.How does this happen?