How to make thread hide in summary buffer by default?

[Zhenqing Li]

Hello guys here:

Each time I enter in one group, like this. The summary buffer expand the 
thread. Then I press T H to hide all thread because I like this format. Can 
somebody tell me how to set this by default in .gnus file?

Thanks!

-- 
Zhenqing Li
Materials Science & Engineering (Emphasis on Polymer)
161 Sirrine Hall, Clemson University, Clemson, SC, 29634, U.S.A
Tel: (864)656-0888, E-mail: zhenqil AT clemson DOT edu
ALL WE SEEN IS ILLUSION.