[填空题]
Unpolarized light passes through filj)1qmo-7 f*gpnky0j t61chpv 1nh:r 6cwa (ave successive Polaroid sheets, each of w/16rl pqp 7ctd l,fjz)wz o;0qhose axis make;7rl 16jwpc,q otzp/qd 0 lz)fs a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam? $I_0$
