The changes that have taken place in air travel during the last sixty years would have
问题描述：
The changes that have taken place in air travel during the last sixty years would have
seemed completely impossible to even the most brilliant scientists at the turn of the 19th century.
怎么翻译呢,句子里的 have taken 是什么时态?
答
过去六十年在航空旅行中发生的变化,即使是19世纪初最棒的科学家好像也认为是不可能发生的.
大概就这个意思吧……我只能翻成这样了,
这里的have taken不能单独提出来,它是和would放在一起的,即would have taken,表过去将来完成时