According to the u. s. census bureau, philadelphia had a population density of 11,379.5 people per square mile in 2010, while the entire u. s. had a population density of 87.4 people per square mile. which best explains the contrast between these two population densities?
while most areas of the u. s. have a high population density, the u. s. encompasses a vast amount of land.
the birthrate decreased throughout the u. s.
while some areas of the u. s. have a high population density, others must have extremely low population densities.
all of the above are correct.

Which of the following statements about protists are true? a.they are typically found in moist environments. b.they are all unicellular. c.they have a nucleus. d.they are all multicellular.

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.

First idea: suddenly, women were leaving their homes to cycle and socialize on country roads and city streets. —wheels of change, sue macy second idea: it was not a stretch for some cyclists to see the possibility of a larger role for women in the world. —wheels of change, sue macy what type of graphic organizer would best represent the connection between these two ideas? 1) a t-chart that separates ideas into two different categories 2) a chronology that shows 3) a sequence of several events a cause-and-effect graphic that shows how one idea led to another 4)a problem-solution graphic that presents a problem and a solution to the problem