The substance is pure depending on which atoms bond.
Hydrogen bonds.
The question asks for bonds BETWEEN molecules NOT WITHIN molecules. A covalent bond occurs WITHIN water molecules between hydrogen and oxygen.
Hydrogen bonds occur BETWEEN water molecules; HYDROGENS of water molecules form a hydrogen bond (a type of intermolecular force) with electronegative OXYGEN atoms of other water molecules.
Cells Can Replicate Their DNA Precisely. Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. DNA replication is one of the most basic processes that occurs within a cell.