—Where is the office?—It's ______ the stairs.A.upB.inC.downD.on

问题描述:

—Where is the office?—It's ______ the stairs.A.upB.inC.downD.on

B.
首先pass A和C,因为那是指向动词,不是介词.on表示在台阶上,in表示在楼道里