3 sentences

1. 红白喜事都要讲究礼节。

   hóng bái xǐ​shì dōu yào jiǎng​jiu lǐ​jié.

   Etiquette must be observed for both weddings and funerals.

   Source: Dong Chinese Dictionary

2. 按照礼节，应该请长辈坐在上手。

   àn​zhào lǐ​jié, yīng​gāi qǐng zhǎng​bèi zuò zài shàng​shǒu.

   According to etiquette, elders should be invited to sit in the seat of honor.

   Source: Dong Chinese Dictionary

3. 在正式场合，必须遵守相应的礼节。

   zài zhèng​shì chǎng​hé, bì​xū zūn​shǒu xiāng​yìng de lǐ​jié.

   At formal occasions, appropriate etiquette must be observed.

   Source: Dong Chinese Dictionary