来自毛建的问题
Hewas_______thepreparationofaninternationalconferencewhenIarrivedinBeijing.A.engagedtoB.engagedforC.engagedonD.engagedin
Hewas_______thepreparationofaninternationalconferencewhenIarrivedinBeijing.
A.engagedto
B.engagedfor
C.engagedon
D.engagedin
