The yearly Marathon (马拉松) in my town usually happened during a heat wave. My job was to
follow behind   _1_   in an ambulance (救护车) in case any of them needed medical attention.
     "We're supposed to stay behind the last runner, so drive it    _2_  ," I said to the driver, Doug, as
the race started.
     The front-runners started to   _3_  and then my eyes were drawn to the woman    _4_  blue silk
running shorts and a white T-shirt.
     We knew we were already watching our "last runner." Her    _5_   were so crippled (残疾的) that
it seemed almost impossible for her to be able to walk, let alone run a marathon.
     Doug and I  _6_  in silence when she slowly moved forward. Finally, she was  _7_  runner left
in sight. Tears streamed down my face when I watched with respect as she pushed forward with great
determination through the last miles.
     When the finishing line came into sight, rubbish was everywhere and the    _8_   crowds had long
gone home. __9_  , standing straight and ever so proud stood a lone man. He was holding one  _10  
of a ribbon (缎带)of crepe paper (皱纹纸) tied to a post (标杆). She slowly crossed through, leaving 
  _11_   ends of the paper fluttering (飘扬) behind her.
     I do not know this woman's name, but that day she became part of my    12 _  a part I often depend
on. For her, it wasn't about    13_  the other runners or winning a prize, but about finishing    _14_  she
had set out to do, no matter what. When I think things are too difficult or I get those "I-just-can't-do-it,"
I think of the last runner. Then I realize how   _15_   the task before me really is.