对教科书中3个句子有疑问有追加（1）Doesaculturalrelicalwayshavetoberareandvaluable?Isitenoughtohavesurvivedforalongtime?Q1:既然“aculturalrelic”作单数讲,那为何是“haveto”而非"hasto”Q

Question

对教科书中3个句子有疑问【有追加】
（1）Does a cultural relic always have to be rare and valuable?Is it enough to have survived for a long time?
Q1:既然“ a cultural relic ”作单数讲,那为何是 “have to ”而非"has to”
Q2:根据上下文"Is it enough to have survived for a long time?"怎么翻译好?
（2）The king of Prussia could never have imagined that his gift to the Russian people would have such an amazing history.
Q3:当我根据意思背诵这一句时错误地把“could never have imagined ”改成“could never imagined”,请问此处可用一般过去时么?

Answer 1

（1）Does a cultural relic always have to be rare and valuable?Is it enough to have survived for a long time?Q1:既然“ a cultural relic ”作单数讲,那为何是 “have to ”而非"has to”因为前面有助动词doe...