I suppose it’s recycle; she’s reusing her own bags.
The notable
hardness of bone is attributed to the presence of inorganic hydroxyapatites.
Due to the calcium salts deposited in it, resulting to the hardness. The
abnormal hardness of bone, which allows it
to resist the compression.
A difference between plant cells and animal cells is that most animal cells are round whereas most plant cells are rectangular. Plant cells have a rigid cell wall that surrounds the cell membrane. Animal cells do not have a cell wall.