阅读下面短文，然后从每小题的四个选项中选出一个可以填入短文中相应空白处的最佳选项。
"What's wrong, dear?" said Mrs. Smith to the little boy, Tom Blair, who had tears in his eyes.
"We have all got a 1 called Little Jim to learn, " said Tom, "and the one who says it best will get a 2 from the teacher. But I don't think I can learn it. "
"Why not?" said Mrs. Smith.
"It is so long and hard for me. And other boys always 3 me, and call me ‘Slow Tom', " said Tom in a 4 voice.
"Well, dear, don't mind 5 others say, " said Mrs. Smith kindly. "Look at that snail (蜗牛) on the wall, how 6 it is! But if you watch it, you will see it will get to the top at last. When you feel like losing heart, 7 the snail on the wall. "
At last, the day came. The teacher called up the boys to repeat (复述) the poem. When five or six boys had tried, it came to Tom's turn. 8 Tom got up, there was a laugh because most of the boys thought he would fail. But he did not 9 a word. And his heart was full of 10 when the teacher said, "Well done, Tom Blair!" After the 11 of the class had tried, the teacher said Tom had done 12 , and he gave him the prize. "And now tell me, " said the teacher, "how you learned the poem so well?"
"Please, sir, it was the snail on the wall that 13 me how to do it, " said Tom. "I saw it crawl up (爬行) the wall bit by bit. It did not stop, nor turn back, but went on and on. And I thought I would do the same with my task. So I 14 learned it bit by bit, and did not give up. "
"Now, boys, let us give a good 15 for Tom Blair and the snail on the wall, " said the teacher. And the old house rang with a loud, long cheer. For all were glad that "Slow Tom" had got a prize at last.
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