Raising taxes was politically unthinkable.
增加税收在政治上来讲是不能考虑的
It is unthinkable that we shall allow a nuclear holocaust to occur.
我们若竟让核武器大屠杀的惨剧发生, 简直是匪夷所思。
It was next to unthinkable that the hunchback came down to the rope as quickly as a monkey.
驼背人从绳子上像猴子一样地滑下来几乎是不可想象的。