Tsis muaj qhov tsis ntseeg vim li cas Canon lub koob yees duab puv ntoob yog ib qhov loj tshaj hauv kev lag luam: lawv muab yam lawv cov neeg sib tw ua tsis tiav. Nrog rau qhov no, nws yog qhov tseeb tias txhua yam koj tab tom nrhiav, Canon lub koob yees duab puv ntoob yuav xa tawm.
