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.
Best Answer: It is normal for a classroom to be in the 68 to 72 range. Sometimes a school has poor insulation and heating and it gets down as low as 60 degrees. Below 60 degrees, you should definitely be asking for help. I suggest you get a cheap wall thermometer and set it where you sit.