Counter current flow is the opposite movement of water against the flow of blood in the fish's gills.
Answer:
Sand
Explanation:
A well should be placed so that contamination from any source moves away from the well and not toward it.
Answer:
Their future children can have blood group AB, O, A or B
Explanation:
since the husband had blood group= Heterogeneous A means AO
and,
the wife's blood group= Heterogeneous B or BO
- so by crossing between them, we get this result.