What do you call a animal with a backbone

Which blood cell spend most of their time in the lymphatic system?

Which is an important function of normal flora? a. aid with bone marrow production. b. crowd out pathogenic bacteria. c. destroy digestive track pathogens. d. manufacture iron in the bloodstream.

Suppose you use three different scale to weigh a bag of oranges. one scale says the nag weighs 2.1 lb, and third says it weighs 2.1 lb. the actual weight of the bag of oranges is 2.153 lb. which of the following best decribes these results?