Which adaptation of a bee is the MOST beneficial for its symbiotic relationship with flowered plants?

What did not occur in the proterozoic eon a)the oxygen levels increase greatly in the atmosphere,b)the emergence of the eukarya , c)muti cella’s eukaryotic organisms began to diversify,d)anaerobic bacteria kept thriving with more oxygen

Which structure in the cardiovascular system connect arteries to veins?

Veronica and her little sister, monique, are playing on a seesaw. if veronica weighs 75 pounds, and monique weighs 60 pounds, which statement is true?