Bone marrow. The inside of your bones are filled with a soft tissue called marrow. There are two types of bone marrow: red and yellow. Red bone marrow is where all new red blood cells, white blood cells, and platelets are made.
Mine is 8m x 7m (3m is 10 feet, so around 27 x 23 feet). This is normal for an Australian classroom, although there's a fair bit of variation.
Day care space with children under 2 years of age -- 55 sq ft per person. 3.6 (13-84-050)(c) Bathroom doors in school corridors. Section (13-80-030) requires all rooms in an institutional occupancy to be separated from the exit corridor by 1-hour fire-rated walls and fire rated doors. There is no such code section for school/assembly occupancies requiring all rooms to be. separated from the exit corridor.