DONT GUVE THE RUGHT ANSWER PREDICT WHY Predict: Why do you think
researchers had problems with low
oxygen levels and increasing
carbon dioxide levels in the
Biosphere 2?

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.

in case if a person is bitten by a snake then after contacting the medical control, there is a need to apply a pressure immobilization bandage and try to make the person calm and as still as possible unless and until any medical comes.

try to avoid washing of the bitten region as any venom left on the skin can in determining the snake. make sure to not cut the wound, or try to suck the venom out from the region, and do not apply any kind of tourniquet.