He busy yesterday, or he you with your experiment.
A. was; had helped
B. was; would have helped
C. had been; would have helped
D. were; would have helped
网友回答
A. was; had helped
(答案→)B. was; would have helped
C. had been; would have helped
D. were; would have helped
解析：本题实际上考察的是or(否则，要不然)引导的含蓄的虚拟条件句。前面句中含有yesterday这个过去时的时间状语，故使用过去时即可。Or后面的句中要使用与过去事实相反的虚拟语气would have done的形式。句义：昨天他很忙，要不然他就会帮助你做实验了。故B正确。