食品生产经营人员
局麻药内加肾上腺素的主要目的是( )
食品生产经营人员
As for a lesson plan ,a teacher says,“When do lesson planning, I always prepare some extra and alternative tasks and activities so that I have the options to cope with the unexpected situations.” According to the teacher’s words, we can know that the teacher follows the principle of ______in lesson planning.