阅读理解。 My friend, Dick, has a large police dog. It's name is Jack. Every Saturday afternoon Dick takes Jack for a long walk in the park. Jack likes these long walks very much. One Saturday afternoon, a young man came to visit my friend. He stayed a long time. He talked and talked. Soon it was time for my friend to take Jack for a walk. But the man was still there. Jack became very worried. He walked around the room several times and then sat down in front of the man and looked at him. But the man kept talking. Finally Jack could stand it no longer. He went out of the room and came back a few minutes later. He sat down again in front of the man, but this time he held the man's hat in his mouth. 1. From the story, we know that Jack is ______. [     ] A. Dick's good friend B. a large police dog C. a young man 2. Where does Dick walk with his dog every Saturday afternoon? [     ] A. In his room B. In the street C. In the park 3. Jack became very worried one afternoon because ______. [     ] A. he couldn't be taken out for a walk at the usual time. B. a young man came to visit Dick that afternoon. C. Dick walked around his room several times. 4. What does the word 'stand' mean in the passage? [     ] A. 站立 B. 理解 C. 忍受 5. Why did Jack sit down again in front of the man with the hat in his mouth? [     ] A Try to take the man laugh. B. Like the young man very much. C. Ask the young man to leave.