During early civilization, the main source of fresh water was from a river. Nowadays, we have reservoirs and lakes to get fresh water. <span />
Ecological succession is the process of change in the species structure of an ecological community over time. The time scale can be decades, or even millions of years after a mass extinction
An empidemic because it kills more people than we can count
<span>The Correct answer is not shown. The correct answer would have to say Atom A has one proton than Atom B because in the question it says Atom A has an atomic number of 19 and Atom B has an atomic number of 20.</span>
