They are dangerous to the environment because they have no natural competition. That being said they have nothing to keep their population in check, therefore, taking away food, and habits from all the other species. Thus, causing species to die out, which in turn ruins the food chain.
There’s actually 100 but only 8 of them infect humans
The pumping force of the ventricles moves blood through the arteries. The breathing movements exerts pressure on the chest veins, the valves in the larger veins keep the blood from flowing backwards, and the skeletal muscles' contraction all help the blood in veins to move.
<span>Capitals: </span><span>Sri Jayawardenepura Kotte, <span>Colombo</span></span>
