阅读下面短文，掌握其大意，然后从16-35各题所给的A、B、C、D四个选项中，选春最佳选项。
The journey my daughter Cathy has had with her swimming is as long as it is beautiful.
Cathy suffered some terrible 16 in her early childhood. After years of regular treatment, she 17 became healthy.
Two years ago, while Cathy was watching the Olympics, a dream came into her sweet little head—to be a swimmer. Last summer, she wanted to 18 out local swim team. She practiced hard and finally 19 it. The team practice, 20 was a rough start. She coughed and choked and could hardly 21 her first few weeks. Hearing her coughing bitterly one night, I decided to 22 her from it all. But Cathy woke me up early next morning, wearing her swimsuit 23 to go! I told her she shouldn’t swim after a whole night’s coughing, but she refused to 24 and insisted she go .
From that day on, Cathy kept swimming and didn’t 25 a single practice. She had a 26 intention within herself to be the best she could be. My ten—year—old was growing and changing right before my eyes, into this 27 human being with a passion and a mission. There were moments of 28 of course: often she would be the last swimmer in the race. It was difficult for Cathy to accept that she wasn’t a 29 ---ever. But that didn’t stop her from trying.
Then came the final awards ceremony at the end of the year. Cathy didn’t expect any award but was still there to 30 her friends and praise their accomplishments. As the ceremony was nearing the end, I suddenly heard the head coach 31 , “The highest honor goes to Cathy!” Looking around, he continued, “Cathy has inspired us with her 32 and enthusiasm. 33 skills and talents bring great success, the most valuable asset(财富)one can hold is the heart.”
It was the greatest 34 of my daughter’s life. With all she hade been 35 in her ten years, this was the hour of true triumph(成功).
33（）
A.Although
B.Since
C.Once
D.Because
拉动小车和木块一起做无相对滑动的加速运动.小车质量是
，木块质量是
，外力大小是
，木块和小车之间的动摩擦因数是
，则在这个过程中，木块受到的摩擦力大小是（ ）
