I grit my teeth and pull out my second knife so that I now have one in each hand. I pray the plaster is soft enough, then leap off the stairs and throw myself toward the wall. 

I stab one knife straight into the plaster. My wounded arm gushes blood, and I scream from the effort. I’m dangling halfway between my launching place and the window. I rock back and forth as hard as I can. 

The plaster is giving way. 

Behind me I hear the laboratory door burst open and soldiers spill out. Bullets spark all around me.

What does the word 'plaster' mean in this quote?

I count off the minutes to keep myself from passing out. Five minutes, ten minutes, thirty minutes, an hour. The footsteps behind me sound far away now, as if they are on a different path than I am. Sometimes I hear strange sounds, something like a bubbling test tube and a sigh of steam pipes, a breath of air. It comes and goes. Two hours. Two and a half hours. When I see the next ladder leading up to the surface, I take my chances and pull myself up. I’m in real danger of fainting now. It takes all my remaining strength to drag myself onto the street. I’m in a dark alley. When I’ve caught my breath, I blink away my fuzzy vision and study my surroundings. 

I can see Union Station several blocks away. I’m not far now. Tess will be there, waiting for me . 

Three more blocks. Two more blocks. 

I have one more block. I can’t hold on any longer. I find a dark spot in the alley and collapse.  

Which word is an example of repetition?