阅读下面短文，从短文后所给的A、B、C、D四个选项中， 选出可以填入空白处的最佳选项

    “It's nice having a friend,” said Mole (鼹鼠) to Rabbit as they sat talking in the sun one day.

    “Oh, it is!” said Rabbit.“Very useful, too, 1 if you need help. 2, I think I'd like Bull(公牛) to be my friend.”

    “But I'm your friend!” said Mole, feeling 3.

    “Oh, yes,” said Rabbit.“You are good for talking to and laughing with, 4you are too small. When I need help, I 5 someone big and strong like Bull.He would be a very good friend to have. It would be 6 shouting for him when I need help.”

    Mole went off in anger.

    “Oh，well，I need to 7 something,” Rabbit thought.

    He moved along 8 he found a tiny garden.He had just started on his first leaf when there was a big 9. People were shouting and dogs were barking(吠叫).Rabbit was so afraid and in such a 10 to get away that he ran into the wrong hole.

    The hole was too 11 and Rabbit got stuck(被卡住).He could not 12 at all.

    “Help!” cried Rabbit.

    Mole 13 him.He ran up to see what was the matter.

    “Help!” cried Rabbit.“I'm stuck in this hole.”

    “If you want help,” said Mole，“I'd better 14 Bull.”

    “No!” cried Rabbit.“He's no good! He's too big to get into this 15.You're just the right 16! Please help me，Mole!”

    So Mole began digging around Rabbit.He 17 so fast that Rabbit was 18 soon.

    “I'm sorry, Mole.I was 19,” Rabbit said.“I'm 20 I have you for a friend.” And so the two good friends set off for home together.