1.
Immutable as my regret.
就像我难解难释的冤屈。
2.
The two brothers set to and fought bitterly.
兄弟俩打起来了, 而且打得难解难分。
3.
be inextricably involved (in a dispute) or locked in a struggle | be sentimentally attached to each other
难分（解）难解（分）
4.
beyond belief or understanding.
难以置信或者难以理解。
5.
relieve suffering, hardship, etc among refugees
解除难民的痛苦、 苦难等
6.
a knotty problem, question, etc
难以解决的疑难、 问题等.
7.
To make obscure or mysterious.
使…难解，使…神秘
8.
a muddled explanation which was scarcely intelligible
难以理解的胡涂解释.
9.
The explanation is not far to seek, ie is very clear.
这种解释不难理解.
10.
Difficult to perceive or grasp by the mind.
难懂的难以理解的或隐晦难懂的
11.
The Problems Concerning Chinese Rural areas,Agriculture,Peasants and Their Solutions;
中国“三农”的无解、难解、必解与破解
12.
The two animals were locked in a fight.
这两头野兽打得难分难解。
13.
Where there is a difficulty, there is a way out .
哪里有困难，哪里就有解决困难的办法。
14.
wrestle with a problem, a difficulty, one's conscience
努力解决难题、 克服困难、 与良心搏斗
15.
Not easy to understand or analyze.
难懂的难于理解或分析的
16.
The pitfall is that the results will be difficult to interpret.
困难在于试验的结果将是难以解释的。
17.
the resolution of a problem, question, difficulty, doubt, etc
难题、 问题、 困难、 疑问等的解决.
18.
A New Interpretation of A Titleless Poem by Li Shang-yin;
李商隐《无题·相见时难别亦难》新解