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?
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?
问题解答：
我来补答展开全文阅读