Answer:
Open circulatory system:
Relies on the heart to keep blood flowing
Used in all vertebrates
Sorry thats all i know :)
The answer to your question is "maggots"
controll is your awser you vary a factor to measure the results
Question 5 is all of the above question 6 is bases that are found on dna question 7 is the one on the top
<span>blood, lungs and blood vessels that make up the circulatory system.
... The network of veins, arteries and blood vessels transports
oxygenated blood from the heart, delivers oxygen and nutrients to the
body's cells and then returns deoxygenated blood back to the heart</span>
