Pishu is located under the spinous process of the 11th thoracic vertebra, 1.5 cun beside it. It has the effect of strengthening spleen and harmonizing stomach, promoting digestion food and dispelling dampness. It is often used to treat vomiting, diarrhea, malnutrition,poor appetite, jaundice, edema, slow shock, limb weakness, etc.

A．The half width of the emission line of the radiation source is much narrower than the half width of the absorption line
B．The half width of the emission line of the radiation source should be almost equal to the half width of the absorption line
C．The half width of the absorption line is much narrower than the half width of the emission line
D．The monochromator must have very high resolution