How does social distancing address the density dependent aspect of this disease?

Because your not close enough to get the virus if you have a mask, but if you don’t wear a mask, social distance is irrelevant because the sneeze or cough travels more that 100 feet and then your caught with the virus.

Explanation:

liquid crystals are matters in a state which have properties between those of conventional liquids and those of solid crystals[1]. liquid crystal is partially ordered and anisotropic. in terms of molecular order, liquid crystal molecules have one-dimensional or two-dimensional long - range order.

i think a) betsy can donate only blood to mark is correct because, mark and betsy have the same blood type. whereas nobody else has b+ blood so betsy can't donate to them.