air castle meaning in English

空中楼阁，妄想。

Short of perfect regional innovation system , national innovation system will be nothing else but air castle
没有健全的区域创新体系,国家创新体系无异于空中楼阁。
" but tell me now , count , " exclaimed albert , delighted at the idea of having to chaperon so distinguished a person as monte cristo ; " tell me truly whether you are in earnest , or if this project of visiting paris is merely one of the chimerical and uncertain air castles of which we make so many in the course of our lives , but which , like a house built on the sand , is liable to be blown over by the first puff of wind ?
“请告诉我，伯爵， ”阿尔贝大声说道，他想到能介绍一位象基督山伯爵这样出色的人物，心里高兴， “请实话告诉我，您访问巴黎的这个计划，究竟是出于真心呢，还是那种我们在人生旅途中逢场作戏常许的空愿，象一座建筑在沙堆上的房屋一样，被风一吹就倒了？ ”