2 sentences for 级 (jí — classifier)

1. 这层楼有二十级台阶。

   zhè céng lóu yǒu èr​shí jí tái​jiē.

   This floor has twenty steps.

   Source: Dong Chinese Dictionary

2. 这艘货轮正在通过三峡大坝的五级船闸。

   zhè sōu huò​lún zhèng​zài tōng​guò Sān​xiá dà​bà de wǔ jí chuán zhá.

   The freighter is passing through the five-stage ship lock of the Three Gorges Dam.

   Source: Dong Chinese Dictionary