Bacteria have a thin cell wall, which stains pink. gram-negative gram-positive both a and b none of the above

On a floor there are several 1-4 mm elongated drops leading away from a body lying in a pool of blood. the the forward wall there is a sigzag pattern and on the walls to the right side there is a linear patter

The body is protected against harmful flu viruses by

Which description provides the best objective summary of the article in the passage?