4 sentences

1. 这条公路笔直地伸向远方。

   zhè tiáo gōng​lù bǐ​zhí de shēn​xiàng yuǎn​fāng.

   The highway stretches straight into the distance.

   Source: Dong Chinese Dictionary

2. 士兵们在操场上笔直地站着。

   shì​bīng men zài cāo​chǎng shàng bǐ​zhí de zhàn zhe.

   The soldiers stood bolt upright on the drill ground.

   Source: Dong Chinese Dictionary

3. 笔直的公路一直向地平线伸展。

   bǐ​zhí de gōng​lù yī​zhí xiàng dì​píng​xiàn shēn​zhǎn.

   The straight highway stretches all the way to the horizon.

   Source: Dong Chinese Dictionary

4. 王宫大门前，两名卫兵笔直地站立着，维持着安全。

   wáng​gōng dà​mén qián, liǎng míng wèi​bīng bǐ​zhí de zhàn​lì zhe, wéi​chí zhe ān​quán.

   Two guards stood straight in front of the palace gate to maintain security.

   Source: Dong Chinese Dictionary