单选题 I ______ the meeting yesterday, but some urgent matter prevented me from coming.
【正确答案】 C
【答案解析】[解析] was/were to have done sth.表示根据计划或安排本来要做某事,但后因故未做。be to do sth.表示根据计划或安排要做某事,或打算要做某事。be about to do sth.表示就要做某事。