What Diverse topography means?

The belmont principle of beneficence requires that: a. subjects derive individual benefit from study participation.b. potential benefits justify the risks of harm.c. the study makes a significant contribution to generalizable knowledge.d. risks are managed so that they are no > minimal.

How did the percentage of americans living on farms change between 1820 and 1850 a. it lowered as many americans were sold into slavery b. it rated the same as people stopped coming to america c. it grew as more people came to america d. it lowered as many americans went to work in factories

Which statement is correct? the speed of the light ray is the same in air and medium a. the speed of the light ray is the same in air and medium b. medium a and medium b have different densities because light refracts at different angles. medium a and medium b have the same density because the light ray strikes both at the same angle.