He transplanted the rare flowers to the botany garden _ it was the best time for them.A.where B.when C.until D.that 为什么选

问题描述:

He transplanted the rare flowers to the botany garden _ it was the best time for them.A.where B.when C.until D.that 为什么选B?

后面的句子表示the best time for them,指出后面的句子是以时间为联系的
答案中,只有when表示时间.