fill (something) up        
phrasal verb with fill verb uk/fɪl/ us/fɪl/
B1 (使)充满;(使)填满
to become full, or to make something become full
  The seats in the hall were filling up fast. 礼堂里的座位很快就坐满了。 
 He filled up the tank with petrol. 他在油箱里加满了汽油。 
 - More examples
 - The waiter immediately filled my glass up again.
 - Fill the bucket up with warm soapy water.
 - Don't fill the cup up so full next time.
 - This container fills up with rainwater and we use it to water the houseplants.
 - I'm glad to see that our charity collection boxes are filling up nicely.