Most dog owners feel that their dogs are their best friends. Almost everyone likes dogs because they try hard to please their owners. One of my favorite stories is about a dog who wanted his owner to please him. One of my friends has a large German shepherd ( ) named Jack. Every Sunday afternoon, my friend takes Jack for a walk in the park. Jack likes these long walks very much. One Sunday afternoon, a young man came to visit my friend. He stayed a long time, and he talked and talked. Soon it was time for my friend to take Jack for his walk, but the visitor didn't leave. Jack became very worried about his walk in the park. He walked around the room several times and then sat down directly in front of the visitor and looked at him. But the visitor paid no attention. He continued talking. Finally, Jack couldn't stand it any longer. He went out of the room and came back a few minutes later. He sat down again in front of the visitor, but this time he held the man's hat in his mouth. German shepherds aren't the only intelligent dogs. Another intelligent dog is a Seeing Eye dog. This is a special dog which helps blind people walk along the streets and do many other things. We call these dogs Seeing Eye dogs because they are the "eye" of the blind people and they help them to "see". Seeing Eye dogs generally go to special schools for several years to learn to help blind people. The sentence "Finally, Jack couldn't stand it any longer." means  _  .
Jack could no longer put up with the visitor Jack could no longer stand but he might sit down Jack was very tired and wanted a rest Jack was very angry with the visitor