[名词解释] 共生

胰头癌主要的症状是（） ["腹痛，腹部不适","消化不良、厌食","进行性黄疸","肝脾大","消瘦乏力"] 亚胺培南与何种药物组成的复方制剂为泰能（） ["西司他丁","舒巴坦","他唑巴坦","克拉维酸","氨曲南"] 拮抗 互生 氨苄西林与何种药物组成的复方制剂为优立新（） ["舒巴坦","他唑巴坦","克拉维酸","氨曲南","西司他丁"] 共生