20、There was a little dog in the street. He liked watching the children play. One day, he followed two children home from school. Suddenly, he saw the children’s house was on fire. He knew he needed to help them right away. So he ran down the street to the fire station, barking all the way.

When he arrived at the fire station，he saw the firemen leaving. He tried to run after them, but he could not keep up. By the time he got back to the house, the street was filled with people. He looked for the children but could not see them. He was very worried.

The firemen worked very hard till the fire was out. A fireman named Jack noticed the little dog under a tree, looking across the street at the burned house.

Jack thought, “The dog could cheer up the kids.” So he brought the little dog over to the children. The little dog could not believe his eyes! The children were safe! He rushed to them. The children held the little dog and felt a little better.

Fill in the blanks according to the passage. Only one word for each blank.

   A little dog and two children are good （1）_______. One day, he found the children’s house （2）_______ after the two children arrived home. At once he ran down to the fire station, barking （3）_______ the street. When he （4）_______ back, he didn’t find the children. He was so worried. Just then a fireman, Jack, helped the （5）_______ dog find the children.