What happens when an acid dissolves

Why does his teacher ask him to balance the equation by including the correct coefficient

When a septic tank backs up a goes in to clean it out

Which are examples of how technology has advanced scientific understanding.1using hot water to sterilize medical equipment.2transplanting a human organ into another individual.3inserting genes from one sheep into another cell to make a cloneunderstanding the different structures that make up a cell.4examining microorganisms from the deepest parts of the ocean