Question 15 of 20:
select the best answer for the question
15. fish respiratory systems exchange gas and receive oxygen at the gills. this oxygen then enters the
blood stream and is pumped through the heart and back through the gills without first returning to the
heart. this order of events best describes which type of circulation system?
o a. single loop
ob. open
c. recycling
od. double loop

 b

Explanation:

An open system is when nutrients and waste are moved through the body   freely through the body cavity, rather than being enclosed in veins.

not only is it colder, it also becomes darker, less salty, and more dense.

the most common type of reef is the fringing reef. this type of reef grows seaward directly from the shore. they form borders along the shoreline and surrounding islands.