3 sentences

1. “亭”字在古汉语中也有高耸、直立的含义。

   “ tíng” zì zài gǔ​hàn​yǔ zhōng yě yǒu gāo​sǒng, zhí​lì de hán​yì.

   The character 'Ting' also has the meaning of 'towering' or 'upright' in ancient Chinese.

   Source: Dong Chinese Dictionary

2. 医生建议他久坐后要起身直立行走几分钟，以缓解腰椎压力。

   yī​shēng jiàn​yì tā jiǔ zuò hòu yào qǐ​shēn zhí​lì xíng​zǒu jǐ fēn​zhōng, yǐ huǎn​jiě yāo​zhuī yā​lì.

   The doctor advised him to stand up and walk for a few minutes after sitting for long periods to relieve pressure on his lumbar spine.

   Source: Dong Chinese Dictionary

3. 他试图在直立的峭壁上攀爬。

   tā shì​tú zài zhí​lì de qiào​bì shàng pān​pá.

   He tried to climb the sheer cliff face.

   Source: Dong Chinese Dictionary