The answer for this question would be Integument, digestive, respiratory and urogenital.
The largest system that contact with the external environment would be integument and digestive. That makes two system has normal flora of microbes and not sterile like the other systems. Normal flora of microbes will prevent the pathogen microbe grows so it gives some benefit.
Answer:
B direct Plant
Explanation:
Direct plant sources are plants or plant products that are directly used by humans
Dissolving is when the solute breaks up from a larger crystal of molecules into much smaller groups or individual molecules. This break up is caused by coming into contact with the solvent. In the case of salt water, the water molecules break off salt molecules from the larger crystal lattice.
The virus' DNA becomes a part of the host cell's DNA, and every time the host cell copies and divides, it also copies viral DNA. The viral DNA may remain inactive (a provirus) for a long time, but it can become active when it frees itself from the host's chromosome, which triggers the lytic cycle.
I forget which one is the virus' DNA
The first option for 1 and the second option for 2