4 sentences

1. 这种下流的玩笑一点也不好笑。

   zhè zhǒng xià​liú de wán​xiào yī​diǎn yě bù hǎo​xiào.

   This kind of dirty joke isn't funny at all.

   Source: Dong Chinese Dictionary

2. “下作”里的“作”读去声，表示下流、卑鄙的意思。

   “ xià​zuo” lǐ de“ zuò” dú qù shēng, biǎo​shì xià​liú, bēi​bǐ de yì​si.

   The character 'zuo' in 'xiazuo' is pronounced in the falling tone, meaning low, mean, or contemptible.

   Source: Dong Chinese Dictionary

3. 在这条河流的下流，水流变得非常平缓。

   zài zhè tiáo hé​liú de xià​liú, shuǐ​liú biàn de fēi​cháng píng​huǎn.

   The current becomes very gentle in the lower reaches of this river.

   Source: Dong Chinese Dictionary

4. 在那个等级森严的社会，这被视为下流职业。

   zài nà​gè děng​jí sēn​yán de shè​huì, zhè bèi shì​wéi xià​liú zhí​yè.

   In that strictly hierarchical society, this was considered a lowly profession.

   Source: Dong Chinese Dictionary