How to refuse someone else's job invitation?

1. Sorry, I have other work to do at hand. Please give this job to someone else.

This work is beyond my responsibility, so you should give it to xxx.

I'm not familiar with this job. Xxx is good at this. Please give it to him.

4. Is this the time? I have an appointment with the leader to visit xxx. Excuse me, please see who has time. Give it to him.

I just have to deal with the urgent task given by the leader at that time. I'm sorry

6.xxx has done this job before, and he has detailed information there. It will be much more convenient for you to find xxx.

7. I'm sorry, I have accepted the job invitation of other colleagues. You find someone else.