三、Cloze Test
      One year, I watched a marathon race in my town. All the participants ran across the starting line and moved forward 　21　 the race began. Before long, most of the runners were out of sight in the distance. I noticed a woman 　22　 ran very slowly, and she soon became the last runner. Even so, she still went on 　23　. Several hours later, she finally reached the finish line. There, a man held one end of a paper ribbon, and 　24　 end was tied to a post. The woman crossed the line and broke the ribbon with a big smile. The runner really moved me to tears. She never thought of 　25　 in the marathon. For her, the race was about finishing something she   26    . Now, when I meet difficulties, I think of the woman. Her experience has encouraged me to do things in a determined way.
【題組】21.
(A)although
(B)if
(C)as
(D)but