These are the following answers to the items
cell engulfs molecules in cell "drinking": pinocytosis<span>
molecules helped by protein; move insoluble molecules across plasma membrane: </span>facilitated diffusion
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molecules move in and out freely from high to low concentration: </span>passive diffusion
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cell engulfs microorganisms in cell "eating": </span>phagocytosis<span>
molecules "pumped" in or out from low to high concentration: </span>active transport<span>
oxygen, carbon dioxide: </span>passive diffusion<span>
transports sodium, potassium: </span>active transport<span>
transports glucose, amino acids: </span>pinocytosis
If both of those sexual partners are faithful to each other, and only have sexual relations with one another, then there isn't a high probability that either of them is going to get HIV. If they want to be sure, they should use protection, such as condoms, to prevent getting HIV through body fluids. And they should always be honest with each other in case one of them has that disease.
A pathogen would first try to infect the body and the body tries its best to defend against the pathogen but when it fails you would be infected and fall sick BUT if you are exposed to the same pathogen when you have fully recovered you would have a slightly better immunity against that pathogen since your body had fought it before
