Hi, Alex and Regina, Thank you for the reply.
I saw the change of the line space with a multi-collums document with Regina's guide. And I understand it now. Thank you very much. BTW, Alex, I omitted the space between my name. I'm Zhu Lihua. Maybe you have heard, In a Chinese name, the first word is Family Name. :D It's different from most of the European and American countries. Very intersting.
