2 sentences

1. 他在会议上演示了一组幻灯片。

   tā zài huì​yì shàng yǎn​shì le yī zǔ huàn​dēng​piàn.

   He presented a set of slides at the meeting.

   Source: Dong Chinese Dictionary

2. 投影仪把幻灯片投影在银幕上。

   tóu​yǐng​yí bǎ huàn​dēng​piàn tóu​yǐng zài yín​mù shàng.

   The projector projects the slides onto the screen.

   Source: Dong Chinese Dictionary