Answer:
i think it's A. why? because bumblebees pollinate flowers making more grow but dragonflies EAT the bees so they'll decrease.
Circulatory system
The circulatory system is the transport system for endocrine information. While the nervous system uses neurons, the endocrine chemicals and hormones must circulate through the body via blood vessels. Many glands in your body secrete hormones into the blood.
<span>contractile vacuole
Contractile vacuoles are organelles that are responsible for excretion function. They perform osmoregulation which manages wastes, water and other needed materials in the cell. They are found in some prokaryoric organisms like the algae, protists, amoeba and other unicellular organisms.
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