Bone marrow is the soft fatty substance inside human or animal bones.
There are 2,000 children worldwide who need a bone marrow transplant.
= marrow
N-UNCOUNT
Bone marrow is the soft fatty substance inside human or animal bones.
There are 2,000 children worldwide who need a bone marrow transplant.
= marrow
N-UNCOUNT
Collins COBUILD Advanced Learner's English Dictionary. Английский словарь Коллинз COBUILD для изучающих язык на продвинутом уровне. 2006