4 sentences

1. 工人们拉起了大坝的闸门。

   gōng​rén men lā​qǐ le dà​bà de zhá​mén.

   The workers raised the sluice gates of the dam.

   Source: Dong Chinese Dictionary

2. 警察在事故现场周围拉起了警戒线。

   jǐng​chá zài shì​gù xiàn​chǎng zhōu​wéi lā​qǐ le jǐng​jiè​xiàn.

   Police cordoned off the scene of the accident.

   Source: Dong Chinese Dictionary

3. 警察已经在建筑物外围拉起了警戒线。

   jǐng​chá yǐ​jīng zài jiàn​zhù​wù wài​wéi lā​qǐ le jǐng​jiè​xiàn.

   The police have already set up a cordon around the perimeter of the building.

   Source: Dong Chinese Dictionary

4. 志愿者们在街头拉起了宣传环保的横幅。

   zhì​yuàn​zhě men zài jiē​tóu lā​qǐ le xuān​chuán huán​bǎo de héng​fú.

   Volunteers put up banners promoting environmental protection on the streets.

   Source: Dong Chinese Dictionary