5 sentences

1. 两国之间建立了长久的友谊。

   liǎng guó zhī​jiān jiàn​lì le cháng​jiǔ de yǒu​yì.

   The two countries have established a long-lasting friendship.

   Source: Dong Chinese Dictionary

2. 两国之间的经贸合作日益密切。

   liǎng guó zhī​jiān de jīng​mào hé​zuò rì​yì mì​qiè.

   Economic and trade cooperation between the two countries is becoming increasingly close.

   Source: Dong Chinese Dictionary

3. 这次访问加深了两国之间的友谊。

   zhè cì fǎng​wèn jiā​shēn le liǎng guó zhī​jiān de yǒu​yì.

   This visit deepened the friendship between the two countries.

   Source: Dong Chinese Dictionary

4. 这条河流是两国之间的自然边界。

   zhè tiáo hé​liú shì liǎng guó zhī​jiān de zì​rán biān​jiè.

   This river is the natural boundary between the two countries.

   Source: Dong Chinese Dictionary

5. 两国之间交换了特派使者以加强联系。

   liǎng guó zhī​jiān jiāo​huàn le tè​pài shǐ​zhě yǐ jiā​qiáng lián​xì.

   The two countries exchanged special envoys to strengthen their connection.

   Source: Dong Chinese Dictionary