If you are being asked for help in something which you (i) can't contribute much to (ii) don't have resources to help, let it be known they are looking at the wrong person. If possible, refer them to a lead they can follow-up on – whether it's someone you know, someone who might know someone else, or even a department.
如果某人请求你帮忙的事属于以下两种情况：1、自己做不了多少贡献；2、没有提供帮助的资源，那就告诉他们找错对象了。如果可能的话，为他们指明一个可以请教的对象——这个对象可以是你认识的人，可以是认识其他人的人，甚至可以是一家机构。