7 sentences

1. 岸边有成群的候鸟在休息。

   àn biān yǒu chéng​qún de hòu​niǎo zài xiū​xi.

   Flocks of migratory birds are resting on the shore.

   Source: Dong Chinese Dictionary

2. 天空中有成群的雁往南飞。

   tiān​kōng zhōng yǒu chéng​qún de yàn wǎng nán fēi.

   Flocks of wild geese are flying south in the sky.

   Source: Dong Chinese Dictionary

3. 成群的小雀在草地上觅食。

   chéng​qún de xiǎo què zài cǎo​dì shàng mì​shí.

   Flocks of small sparrows are foraging on the grass.

   Source: Dong Chinese Dictionary

4. 广阔的草原上奔驰着成群的牛羊。

   guǎng​kuò de cǎo​yuán shàng bēn​chí zhe chéng​qún de niú yáng.

   Herds of cattle and sheep are running across the vast grasslands.

   Source: Dong Chinese Dictionary

5. 每年秋天，成群的鲑鱼都会游回上游产卵。

   měi nián qiū​tiān, chéng​qún de guī​yú dōu huì yóu​huí shàng​yóu chǎn​luǎn.

   Every autumn, schools of salmon swim back upstream to spawn.

   Source: Dong Chinese Dictionary

6. 成群的大雁正排成一字形，缓缓地向南方飞去。

   chéng​qún de dà​yàn zhèng pái​chéng yī​zì​xíng, huǎn​huǎn de xiàng nán​fāng fēi qù.

   Flocks of wild geese are flying slowly south in a single-file formation.

   Source: Dong Chinese Dictionary

7. 火车穿过广阔的平原时，我看到了窗外成群的牛羊。

   huǒ​chē chuān​guò guǎng​kuò de píng​yuán shí, wǒ kàn​dào le chuāng wài chéng​qún de niú yáng.

   As the train crossed the vast plains, I saw herds of cattle and sheep outside the window.

   Source: Dong Chinese Dictionary