则and所is not a conbination. 则in thise sentence means however,meanwhile. 所in this sentense means what...,which...,where...,and so on i give u same eg. about 所: 我所说的——what I say : 我所有的——what i have; 你所做的——what you do;我所住的地方——the palce where I live; 战争所带来的毁坏——the damage which cause by war