B2 adjective /ʌnˈθɪŋkəbl/
Unthinkable
难以想象的
Meaning
impossible to conceive or imagine; beyond belief or consideration
Example
It was unthinkable that such a tragedy could happen in our peaceful town.
在我们和平的小镇上发生这样一场悲剧,简直是难以想象的。