Definition: If something is unthinkable, it is so strange that you cannot imagine it will ever happen. Level: C1
三十年前，无烟餐厅是不可想象的。
Thirty years ago a no-smoking restaurant would have been ___unthinkable.
如今，没有电脑的生活简直是不可想象的。
Nowadays it is simply ___unthinkable to live without a computer.
对他来说，失败是不可想象的；他总是追求完美。
For him, failure is ___unthinkable; he always strives for perfection.
