<span>Answer: Bone marrow stem cells have been shown to generate cartilage, bone, and muscle when injected directly into the injured site
Stem cells could differentiate into the various type of cells, makes them able to regenerate part of the body that doesn't have regeneration abilities. The cell that involved the </span><span>tear of the rotator cuff would be cartilage, bone, and muscle. Stem cells could replace the damaged cells so that the muscle and joint might work better. </span>
I don’t know why they make everyone type more than 20 characters but B sounds like the most reasonable answer.
You should get rid of any distractions so you can focus.
