难题

nán tí jiù zài zhè

难题就在这。

This is where the difficulty lies.

wǒ men dāng qián yǒu yī gè nán tí

我们当前有一个难题。

We are facing a conundrum.

wǎng luò ān quán shì hù lián wǎng fā zhǎn de yī dà nán tí

网络安全是互联网发展的一大难题。

Network security is a major challenge to the development of the Internet.

shè zhì nán tí

设置难题

set difficult questions

jiě jué nán tí

解决难题

solve a difficulty

zhèng zhì nán tí

政治难题

political difficulty

chǔ lǐ nán tí

处理难题

handle a hot potato

rú hé tí gāo chǎn pǐn zhì liàng duì tā lái shuō shì gè nán tí

如何提高产品质量对他来说是个难题。

How to improve the quality of products was a difficult problem to him.

suàn shù nán tí

算术难题

arithmetic brain-teaser

wǒ chōng fèn liǎo jiě nǐ zāo yù dào le nán tí dàn shì wǒ kǒng pà wú fǎ bāng zhù nǐ

我充分了解你遭遇到了难题，但是我恐怕无法帮助你。

I fully appreciate that you have met with problems, but I'm afraid I can't help you.