4 sentences

1. 这是前所未有的！

   zhèi shì qián​suǒ​wèi​yǒu de!

   This is unprecedented!

   Source: OpenSubtitles

2. 我们正面临着前所未有的挑战。

   wǒ​men zhèng miàn​lín zhe qián​suǒ​wèi​yǒu de tiǎo​zhàn.

   We are facing unprecedented challenges.

   Source: Dong Chinese Dictionary

3. 这次疫情带来了前所未有的挑战。

   zhè cì yì​qíng dài​lái le qián​suǒ​wèi​yǒu de tiǎo​zhàn.

   The pandemic has brought unprecedented challenges.

   Source: Dong Chinese Dictionary

4. 环球经济正面临前所未有的挑战。

   huán​qiú jīng​jì zhèng miàn​lín qián​suǒ​wèi​yǒu de tiǎo​zhàn.

   The global economy is facing unprecedented challenges.

   Source: Dong Chinese Dictionary