On the map of the united states shown below, four lines have been drawn and labeled a, b, c, and d

the length of which line best represents the distance from earth’s surface to the top of the mesosphere?
(1) a
(2) b
(3) c
(4) d

Which of the following statements best describes what is occurring in the land surrounding the sahara desert? a desertification is increasing, and the desert is expanding. b. fewer people are trying to farm in this semiarid region. c. the desert is shrinking with the increased use of irrigation. d. increased urbanization has resulted in decreased deforestation. select the best answer from the choices provided mark this and return save and exit next submit