4 sentences

1. 他写了本关于美国南北战争的书。

   tā xiě le běn guān​yú Měi​guó nán​běi zhàn​zhēng de shū.

   He wrote a book about the American Civil War.

   Source: Tatoeba

2. 中国南北的饮食习惯有很大差异。

   Zhōng​guó nán​běi de yǐn​shí xí​guàn yǒu hěn dà chā​yì.

   There are major differences in dietary habits between northern and southern China.

   Source: Dong Chinese Dictionary

3. 古人在茫茫大海上常根据北斗的方向来辨别南北。

   gǔ​rén zài máng​máng dà​hǎi shàng cháng gēn​jù Běi​dǒu de fāng​xiàng lái biàn​bié nán​běi.

   Ancient people often relied on the direction of the Big Dipper to tell north from south at sea.

   Source: Dong Chinese Dictionary

4. 这条铁路线贯通南北。

   zhè tiáo tiě​lù​xiàn guàn​tōng nán​běi.

   This railway line connects the north and the south.

   Source: Dong Chinese Dictionary