3 sentences

1. 楚国是战国七雄之一。

   Chǔ​guó shì zhàn​guó​qī​xióng zhī yī.

   The State of Chu was one of the Seven Warring States.

   Source: Dong Chinese Dictionary

2. 燕国是战国七雄之一。

   Yān​guó shì zhàn​guó​qī​xióng zhī yī.

   The State of Yan was one of the seven powerful states of the Warring States period.

   Source: Dong Chinese Dictionary

3. 在战国七雄中，韩的疆域范围在后期不断缩小。

   zài zhàn​guó​qī​xióng zhōng, Hán de jiāng​yù fàn​wéi zài hòu​qī bù​duàn suō​xiǎo.

   Among the Seven Warring States, the territory of Han continuously shrank in the later period.

   Source: Dong Chinese Dictionary