A.When it occurs ina patient with alcoholic liver disease，it is always due to oesophageal varices.
B.A visible vessel seen at gastroscopy is not a risk factor for further bleeding.
C.When it occurs in patientsover 70 years of age who may have arthritis，ususlly indicates malignancy.
D.When it occurs afrer repeated retching，it is suggestive of an oesophageal tear.
E.When it is caused by duodenal ulcer，a partial gastrectomy is usually necessary.