4 sentences

1. 密切注视他。

   mì​qiè zhù​shì tā.

   Keep a close eye on him.

   Source: OpenSubtitles

2. 机长在驾驶舱里密切注视着飞行仪表。

   jī​zhǎng zài jià​shǐ​cāng lǐ mì​qiè zhù​shì zhe fēi​xíng yí​biǎo.

   The captain was in the cockpit, closely monitoring the flight instruments.

   Source: Dong Chinese Dictionary

3. 救生员正在海滩上密切注视着游泳者。

   jiù​shēng​yuán zhèng​zài hǎi​tān shàng mì​qiè zhù​shì zhe yóu​yǒng zhě.

   Lifeguards are keeping a close watch on swimmers at the beach.

   Source: Dong Chinese Dictionary

4. 飞行员正在密切注视着驾驶舱内的仪表。

   fēi​xíng​yuán zhèng​zài mì​qiè zhù​shì zhe jià​shǐ​cāng nèi de yí​biǎo.

   The pilot is closely watching the instruments in the cockpit.

   Source: Dong Chinese Dictionary