unsolvable

adj.

不能解决的，无法解释的，不能溶解的；

1. This is no unsolvable problem if we face it wisely and courageously.
   我们只要明智而勇敢地承担起来，这项任务并不是不能解决的。
2. None of Russia's problems is unsolvable, but all require strategy and transparency rather than overconfident rhetoric.
   没有一个俄罗斯的问题是不能解决的，但是所有这些都需要有策略及透明度，而不是自负的夸夸其谈。

Unsolvable Classes of Quantificational Formulas
Hilbert's Tenth Problem is Unsolvable
A power flow measure for unsolvable cases
A variant of a recursively unsolvable problem
Review: Alonzo Church, An Unsolvable Problem of Elementary Number Theory
An Elementary Construction of Unsolvable Word Problems in Group Theory *
Computability & Unsolvability.Hilbert's Tenth Problem is Unsolvable
Cerebral blood flow changes in limbic regions induced by unsolvable anagram tasks.
Unsolvable Fear, Trauma, and Psychopathology: Theory, Research, and Clinical Considerations Related to Disorganized Attachment Acros...
Optimism and Self-Mastery Predict More Rapid Disengagement from Unsolvable Tasks in the Presence of Alternatives