难以的英文：
hard to

参考例句：

It is hard to retrieve
难以挽回

A formidable challenge;a formidable opponent.
难以应付的挑战;难以对付的对手

Difficult to comprehend or see;illegible.
难以理解的难以理解或看清的;难认的

a formidable question
难以回答的问题

unbreathable exhaust fumes.
令人难以呼吸的废气

Difficult to penetrate or understand; recondite
难以理解的;不易懂的

There was too little food to support life.
食物太少，难以维持生命。

Difficult terrain for cycling
骑自行车难以行走的地带

Difficult to comprehend or see; illegible.
难以理解或看清的;难认的。

Rocky earth plows poorly.
硬地难以受犁

hard是什么意思：
adj. 硬的，坚固的；困难的；有力的；冷酷无情的
adv. 努力地；困难地；严重地，猛烈地

It is hard to conclude.
这很难断定。

It is blowing hard.
风刮得很大。

It was sleeting hard.
雨雪霏霏。

To bear hard upon;press.
使痛苦不堪对某人施加困难；逼迫

press hard upon
进逼|压迫|穷追