D It was Sunday morning. All the summer world was bright and fresh, and full of life. There was cheer on every face and a spring in every step. Tom appeared on the sidewalk with a bucket of whitewash and a long-handled brush. He stopped by the fence in front of the house where he lived with his aunt Polly. He looked at it, and all joy left him. The fence was long and high. He put the brush into the whitewash and moved it along the top of the fence. He repeated the operation. He felt he could not continue and sat down. He knew that his friends would arrive soon with all kinds of interesting plans for the day. They would walk past him and laugh. They would make jokes about his having to work on a beautiful summer Saturday. The thought burned him like fire. He put his hand into his pockets and took out all that he owned. Perhaps he could find some way to pay someone to do the whitewashing for him. But there was nothing of value in his pockets—nothing that could buy even half an hour of freedom. So he put the bits of toys back into his pockets and gave up the idea. At this dark and hopeless moment, a wonderful idea came to him. It filled his mind with a great, bright light. Calmly he picked up the brush and started again to whitewash. While Tom was working, Ben Rogers appeared. Ben was eating an apple as he walked along the street. As he walked along, he was making noises like the sound of a riverboat. First he shouted loudly, like a boat captain. Then he said “Ding-Dong-Dong”, “Ding-Dong-Dong” again and again, like the bell of a riverboat. And he made other strange noises. When he came close to Tom, he stopped. Tom went on whitewashing. He did not look at Ben. Ben stared a moment and then said: 'Hello! I’m going swimming, but you can’t go, can you?” No answer. Tom moved his brush carefully along the fence and looked at the result with the eye of an artist. Ben came nearer. Tom's mouth watered for the apple, but he kept on working. Ben said, 'Hello, old fellow, you’ve got to work, hey?' Tom turned suddenly and said, 'Why, it's you, Ben! I wasn't noticing.' 'Say — I'm going swimming. Don't you wish you could? But of course you’d rather work — wouldn't you? Of course you would.' Tom looked at the boy a bit, and said 'What do you call work?' 'Why, isn't that work?' Tom went back to his whitewashing, and answered casually, 'Well, maybe it is, and maybe it isn't. All I know is, it suits Tom Sawyer.' 'Oh come, now, you don't mean to say that you like it?' The brush continued to move. 'Like it? Well, I don't see why I shouldn’t like it. Does a boy get a chance to whitewash a fence every day?' Ben stopped eating his apple. Tom moved his brush back and forth, stepped back to look at the result, added a touch here and there, and stepped back again. Ben watched every move and got more and more interested. Soon he said, 'Say, Tom, let me whitewash a little.' Tom thought for a moment, was about to agree; but he changed his mind: 'No — no — it won’t do, Ben. You see, Aunt Polly wants this fence to be perfect. It has got to be done very carefully. I don’t think there is one boy in a thousand, maybe two thousand, that can do it well enough.' 'No — is that so? Oh come, now —let me just try. Only just a little.' 'Ben, I'd like to, but if it isn’t done right, I’m afraid Aunt Polly— ' 'Oh, I'll be careful. Now let me try. Say -- I'll give you the core（核心）of my apple.' 'Well, here — No, Ben, now don't. I'm afraid —' 'I'll give you all of it.' Tom gave up the brush with unwillingness on his face, but joy in his heart. And while Ben worked at the fence in the hot sun, Tom sat under a tree, eating the apple, and planning how to get more help. There were enough boys. Each one came to laugh, but remained to whitewash. By the time Ben was tired, Tom sold the next chance to Billy for a kite; and when Billy was tired, Johnny bought in for a dead rat — and so on, hour after hour. And when the middle of the afternoon came, Tom had won many treasures And he had not worked. He had had a nice idle time all the time, with plenty of company -- and the fence had been whitewashed three times. If he hadn't run out of whitewash, Tom would have owned everything belonging to his friends. He had discovered a great law of human action, namely, that in order to make a man or a boy want a thing, it is only necessary to make the thing difficult to get. 68．Tom was about to agree to let Ben whitewash when he changed his mind because ______ . A. Tom wanted to do the whitewashing by himself B. Tom was unwilling to let Ben do the whitewashing C. Tom was afraid Ben would do the whitewashing better D. Tom didn’t want to let Ben do the whitewashing before he made him give up his apple first 69．The underlined word “casually” is most similar to “______” in meaning. A. carelessly                 B. delightedly               C. seriously                  D. angrily 70．We can learn from the passage that ______ . A. Tom was interested in whitewashing the fence. B. Tom had a lot of friends who are ready to help others. C. Tom was unwilling to whitewash the fence, but he managed to let other boys do it for him D. Tom was good at whitewashing the fence, so he looked at the result of his work with the eye of an artist.