Answer: Ecosystem
Explanation: An ecosystem consists of all the biotic and abiotic factors in an area and their interactions. A niche refers to the role of a species in its ecosystem. A habitat is the physical environment in which a species lives and to which it is adapted.
Answer: Hydrogen bonds.
Explanation: This seems like more of a chemistry question, but basically hydrogen bonding is way stronger than any other kinds of bonding, and because water molecules are all hydrogen bonded, they cling together a bunch and are thus super cohesive.
A) It would die as harmful substances entered the cell
Answer:
Following are the salient adaptations of villi that make them good absorbers:
Villi are single cell thick. ...
Villi have rich network of blood capillaries . ...
Most important is: Apical membranes of Villi further form many finger-like projections called microvilli or brush borders. ...
Villi have permeable membranes .