3 sentences

1. 纸上写满了密密麻麻的字。

   zhǐ shàng xiě​mǎn le mì​mi​má​má de zì.

   The paper was covered with dense handwriting.

   Source: Dong Chinese Dictionary

2. 墙上布满了密密麻麻的弹孔。

   qiáng shàng bù​mǎn le mì​mi​má​má de dàn​kǒng.

   The wall was riddled with bullet holes.

   Source: Dong Chinese Dictionary

3. 地上的蚁群正密密麻麻地向饼干屑爬去。

   dì shàng de yǐ qún zhèng mì​mi​má​má de xiàng bǐng​gān xiè pá qù.

   The swarm of ants on the ground is crawling thickly toward the cookie crumbs.

   Source: Dong Chinese Dictionary