单选题He ______busy yesterday or&nbs

问题补充：

单选题He______busyyesterday,orhe______youwithyourexperiment.A.was;had helpedB.was;would have helpedC.had been;would have helpedD.were;would have helped

答案：

B解析该题根据交际情景考查时态的用法。第一句有明确的时间状语yesterday，故用过去时。后一句表示过去的动作并没有发生，故用“would have done”。