3 sentences

1. 海军舰艇正在领海进行例行巡航。

   hǎi​jūn jiàn​tǐng zhèng​zài lǐng​hǎi jìn​xíng lì​xíng xún​háng.

   Naval vessels are conducting routine patrols in territorial waters.

   Source: Dong Chinese Dictionary

2. 这艘强大的战舰正在公海上执行巡航任务。

   zhè sōu qiáng​dà de zhàn​jiàn zhèng​zài gōng​hǎi shàng zhí​xíng xún​háng rèn​wu.

   This powerful warship is carrying out a patrol mission on the high seas.

   Source: Dong Chinese Dictionary

3. 由于天气良好，飞机很快进入了巡航状态。

   yóu​yú tiān​qì liáng​hǎo, fēi​jī hěn kuài jìn​rù le xún​háng zhuàng​tài.

   Due to the good weather, the plane quickly reached its cruising speed.

   Source: Dong Chinese Dictionary