When Steven suddenly remembered that he had left his mobile in the office, the train was already ________.

A．on the go

B．on the rise

C．on the run

D．on the move

西司他丁与亚胺培南配伍的主要目的是（）

A.提高对β-内酰胺酶的稳定性

B.降低亚胺培南的不良反应

C.防止亚胺培南在肾中破坏

D.防止亚胺培南在肝脏代谢

E.延缓亚胺培南耐药性的产生