Explain the relationship between polio, typhus , WWII and DDT

Which of the following areas have the highest population density? a) quebecb) united statesc) californiad) new york city

Which evidence is most likely used to indicate the beginning of solar system formation? a. materials combined to form a mass. b. materials were pulled together by gravity. c. water condensed and collected to form oceans. d. different species of microorganisms lived on earth.

What weather system might be occurring if the pressure gradient decreases and fish harvests in peru are weaker than normal