3 sentences

1. 他在比赛中一直处于领先地位。

   tā zài bǐ​sài zhōng yī​zhí chǔ​yú lǐng​xiān dì​wèi.

   He has been in the lead throughout the competition.

   Source: Dong Chinese Dictionary

2. 中国的航天技术处于世界领先地位。

   Zhōng​guó de háng​tiān jì​shù chǔ​yú shì​jiè lǐng​xiān dì​wèi.

   China's aerospace technology is in a leading position in the world.

   Source: Dong Chinese Dictionary

3. 明朝时期的航海技术在当时的世界处于领先地位。

   Míng​cháo shí​qī de háng​hǎi jì​shù zài dāng​shí de shì​jiè chǔ​yú lǐng​xiān dì​wèi.

   Navigation technology during the Ming Dynasty was at the forefront of the world at that time.

   Source: Dong Chinese Dictionary