Linda was _ the experiment a month ago but she changed her mind at the last minute.
问题描述：
Linda was _ the experiment a month ago but she changed her mind at the last minute.
A.to start B.to have started C.to be starting D.to have been starting
答
答案B
解析：was to 是表示过去将来,Linda 在1个月前,准备做实验,在那个时候,做实验这件事是将来时.have +动词过去分词,表示本来要做而没有做.本来Linda要做实验的,结果没有做.
整句话的意思是【Linda在一个月前本来要做实验的,但是她在最后一分钟的时候改变主意了.】