9)
Tommy was walking at a rate of 4
miles
hour
at noon and at 12:30 pm he was walking at a brisk rate of 6
miles
hour
. Two hours later Tommy was walking at a leisurely rate of 2
miles
hour
. Which statement about Tommy's accleration is true?
A) Tommy had an accleration of zero the entire time.
B) Tommy had a positive acceleration between noon and 12:30 pm.
C) Tommy had a positive acceleration between 12:30 and 2:30 pm.
D) Tommy had a negative acceleration between noon and 12:30 pm.

Genetic diversity is the variation in the genes of an entire species. each circle represents a population of a particular species in different habitats. select the population with maximum genetic diversity

Which of the following statements are true chromosomes make up genes

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area