What role does heat play in the formation of convection currents? Choose the correct answer. a) When water loses heat, it becomes denser and sinks. b) When water gains heat, it becomes denser and sinks. c) When water loses heat to cooler water, the cooler water becomes denser and sinks. d) When water gains heat, it dissolves more solids and gases, becomes denser, and sinks.

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