Answer:
Water (H2O) can be called a molecule or a compound because it is made of hydrogen (H) and oxygen (O) atoms. There are two main types of chemical bonds that hold atoms together: covalent and ionic/electrovalent bonds. Atoms that share electrons in a chemical bond have covalent bonds.
 
        
             
        
        
        
The correct answer is "<span>they can develop into most types of human cells".
Stem cells are cells that are undifferentiated to what function they may serve, depending on the tissue where it will develop in to. In the context of brain tissue implants, these stem cells can develop into brain cells or nerve cells or neurons which comprises the functional brain tissue; this is clinically significant as neurons are not capable of replacing themselves if damaged.</span>