题目内容：

Every evening, Blackie would be waiting for Alan to come back from school. He would greet Alan with a woa woa 1.__________ a wagging tail. Blackie was a dog and Alan was his master. Blackie liked to play with Alan.

One evening when Alan returned from school, there was no woa woa and a wagging tail. Blackie was missing. Early the next morning, Alan and his brother went2.___________ (look) for Blackie. They walked and searched from morning to evening, 3.____________(shout) “Blackie, Blackie!”But there was no woa woa and a wagging tail. 4._______________ children were very sad and tired.

One day, the children heard a woa woa coming from a house. It sounded like Blackie. The children ran to the house and 5._____________(ring) the bell. A man opened the door. The children asked,“Uncle, have you seen a black dog?” The man replied,“No.”But the children still heard a woa woa coming6.__________ the house.

The children decided to climb a small hill 7._______________ leads to the back of the house. It was not easy to climb the hill. They had to hold on to twines and pull8._____________ (they) up the slope. When the children reached the top, they saw Blackie tied to a chain. Then the man realized that he could no longer hide the 9._____________(true) from the children so he returned Blackie to them. Blackie looked 10._____________(happiness) and greeted the children with a woa woa and a wagging tail.