题目内容：
阅读短文，完成填空：A young man was getting ready to graduate from college, for many months he had admired a beautiful sports car in a dealer's showroom, and 21 his father could well afford it, he told him that was all he wanted．
On the morning of his graduation day, his father called him into his own study and told him how 22 he was to have such a fine son. He handed his son a beautiful gift box. Curious but slightly disappointed, the young man 23 the box and found a lovely book. Angrily, he raised his voice at his father and said．" 24 all your money you give me a book? " And rushed out of the house leaving the book in the study.
He did not contact his father for a whole year 25 one day he saw in the street an old man who looked like his father. He realized he had to go back home and see his father.
When he arrived at his father's house, he was told that his father had been in hospital for a week. The moment he was about to 26 the hospital. He saw on the desk the still new book, just as he had left it one 27 ago. He opened it and began to turn the pages. Suddenly, a car key 28 from an envelope taped behind the book, it had a tag with dealer's name, the same dealer who had the sports car he had 29 on the tag was the date of his graduation, and the 30 :
PAID IN FULL.
A．finding
A．finding
A．finding
A．finding
B．proving
B．proving
B．proving
B．proving
C．deciding
C．deciding
C．deciding
C．deciding
D．knowing
D．knowing
D．knowing
D．knowing
参考答案：
答案解析：