[填空题]
A series of polarizerxwq+f /c/ jy8b :ss)fqx0jw e4s are e6up y,-1fyup,:wowju;n n 1/q (n r 8,kymnzyhach placed at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?
