The main function of the circulatory system is to move blood and lymph<span> through the body. Doing this transports nutrients and oxygen to the cells of the body and removes waste products such as carbon dioxide.</span>
Answer:
<h2>Jupiter, earth ,venus,Mars, Uranus </h2>
A keystone species helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.