Biology help? 10 points best answer...?

[Henry]

1. Based on the diagram, oxygen flows through the circulatory system in which order?

http://i253.photobucket.com/albums/hh74/terrib_02/bio1.jpg

a. 2, 1, 3
b. 5, 3, 1
c. 3, 2, 4
d. 1, 2, 4


2. Where in the diagram does oxygen first enter the bloodstream?

http://i253.photobucket.com/albums/hh74/terrib_02/VHS_BIO_S2_03_18_heartlungcycle.jpg

a. 2
b. 3
c. 4
d. 5


3. Which statement best describes the role of the lung in gas exchange?

a. It takes in oxygen from the bloodstream.
b. It produces carbon dioxide as a waste product of cellular respiration.
c. It extracts oxygen from the atmosphere for use by body cells.
d. It provides carbon dioxide to the capillaries.