题目

 LEEDS, England-A Leeds University psychology professor is teaching a course to help dozens of people forgive their enemies. “The hatred (憎恨) we hold within us is a cancer,”Professor Ken Hart said, adding that holding in anger can lead to problems such as high blood pressure and heart disease. More than 70 people have become members in Hart’s first 20-week workshop in London—a course he says is the first of its kind in the world. These are people who are sick and tired of living with a memory. They realize their bitterness is a poison they think they can pour out, but they end up 反比例函数y=3-kx的图象的一支位于第四象限，（1）图象的另一支位于第 象限．（2）常数k的取值范围是什么？（3）在这个函数图象的某一支上任取点A（a，b）和点B（c，d），如果b＜d，那么a与c有怎样的大小关系？