3 sentences

1. 大雁在秋天向南方飞去。

   dà​yàn zài qiū​tiān xiàng nán​fāng fēi​qù.

   Wild geese fly south in the autumn.

   Source: Dong Chinese Dictionary

2. 大雁秋天往南方飞，春天回到北方。

   dà​yàn qiū​tiān wǎng nán​fāng fēi, chūn​tiān huí​dào běi​fāng.

   Wild geese fly south in autumn and return to the north in spring.

   Source: Dong Chinese Dictionary

3. 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