<span>a nucleus in an electron cloud.</span>
i think you mean antibiotic ... but Alexander Fleming was the one who advanced the antibiotic (world) and was responsible for creating these categories of medicine... this affected the 20th century because millions of people use antibiotics everyday and without them... many diseases would still affect people without a cure
C) New settlers arrived at a steady rate and the population increased gradually
I mean you cant google it and find the answer cmon
