When ________, themuseum will be open to the public next year.
A.completedB.completingC.beingcompletedD.to becompleted在线课程A
complete和museum是动宾关系，要用过去分词completed作状语，表示被动。句意：当这座博物馆建成后，将在明年向公众开放。to be completed作目的状语，不与when连用。