[填空题]
A light meter reports that0(6g*lhds kym a camera settige9-l hk3yrl/7 gw/fzng of $\frac{1}{250}\,s$ at $f/5.6$ will give a correct exposure. But the photographer wishes to use $f/11$ to increase the depth of field. What should the shutter speed be?$t_2$ = 1/ s
