4 sentences

1. 无数条小溪最后汇聚成了大河。

   wú​shù tiáo xiǎo​xī zuì​hòu huì​jù chéng le dà hé.

   Countless small streams eventually merge into a large river.

   Source: Dong Chinese Dictionary

2. 许多细小的水流最终汇聚成了大河。

   xǔ​duō xì​xiǎo de shuǐ​liú zuì​zhōng huì​jù chéng le dà hé.

   Many tiny streams eventually converged into a large river.

   Source: Dong Chinese Dictionary

3. 海内外俊彦汇聚于此，共商科学发展大计。

   hǎi​nèi​wài jùn yàn huì​jù yú cǐ, gòng​shāng kē​xué fā​zhǎn dà​jì.

   Eminent talents from home and abroad gathered here to discuss major plans for scientific development.

   Source: Dong Chinese Dictionary

4. 全世界的顶尖科学家都汇聚在这里参加会议。

   quán shì​jiè de dǐng​jiān kē​xué​jiā dōu huì​jù zài zhè​lǐ cān​jiā huì​yì.

   Top scientists from all over the world have gathered here for the conference.

   Source: Dong Chinese Dictionary