unthinkable

adj.

无法想象的；难以置信的；不能考虑的；绝不可能的

1. It would be unthinkable to ask him to do that.
   叫他做那件事是毫无可能的。
2. Only the effort of the group can make some unthinkable become thinkable.
   大家的努力把一件不可能的事变成可能的。
3. That this project would achieve ultimate success was unthinkable at the time.
   这个项目能获得最后的成功在当时对人们来说是难以置信的。
4. The stars are an unthinkable distance from the earth.
   恒星和地球的距离是难以想像的。

Managing the unthinkable
Thinking about the Unthinkable.
The Psychology of the Unthinkable
Unthinkable democracy: Political change in advanced industrial democracies
Crisis leadership: Planning for the unthinkable
How Unthinkable and At What Age?: Adult Opinions about the ‘Social Clock’ for Contested Behaviour by Teenagers
The psychology of the unthinkable: taboo trade-offs, forbidden base rates, and heretical counterfactuals.
India and Pakistan: Thinking about the Unthinkable - war game scenario involving nuclear weapons
Young Children's Aspirations in Science: The unequivocal, the uncertain and the unthinkable
Clinical consequences of polypharmacy in elderly: expect the unexpected, think the unthinkable.