What type of blood vessel returns blood to the heart?
a. artery
b. vein
c. capillary
d. none of the above

When organisms are classified ,they are given a two part name

What is the difference between bacterial infections and viral infections?

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