From industrial beginnings in the nineteenth century, plastics______through a hundred and twenty years of glory, failure, disrepute and suspicion on the slow road to public acceptance. A．struggled B．have struggled C．are struggling D．has struggled
A. A．struggled B．have B.are C.has
【参考答案】
B 从选项的区别点来看，此题的考点是时态，这时考生就应该回到题句中找时间状语，已给的或暗示的。这个句子的时间状语......