 3. Subjects with high gastrointestinal bleeding risk, including the following conditions: local active ulcer lesions with positive fecal occult blood test ; history of black stool, or vomiting blood in the past 3 months;unresected primary lesion in stomach with positive fecal occult blood test , ulcerated gastric carcinoma with massive alimentary tract bleeding risk judged by PIs based on gastric endoscopy result; 