题目

Jack Evans quarreled with his neighbour，Ellen Brown. Mrs. Brown had a dog. Jack did not like dogs. He wanted Mrs. Brown to give away or sell her dog，but she refused. “I'll take you to court if you don't，” he said. Mrs. Brown laughed at him. She was not worried. Jack thought，“I must talk to a lawyer，but lawyers are expensive. I don't want to waste my money. I will waste it if I don't win my case against Mrs. Brown and her dog.” Then Jack had an idea. There was a young lawyer in the town. He did not have much work. Not many people knew about him. “I'll visit him如果代数式+有意义，那么直角坐标系中点A（a，b）的位置在（ ）A．第一象限B．第二象限C．第三象限D．第四象限