have加动词ing是什么时态

　　I'm having treatment for my back problem.

　　我正接受背部疾患的治疗。

　　Few people can count on having a job for life.

　　几乎没有人能指望一辈子都干一个工作。

　　Having good personal relationships is the most important thing for me.

　　拥有良好的人际关系对我最为重要。

　　I'm always having to clean up after the children.

　　孩子们离开以后，我总得打扫一番。

　　Don't give me that line about having to work late again.

　　别再跟我说不得不工作到很晚这样的话。