true or false. the crab nebula is a planetary nebula.

Which of the following areas has the highest population density?

Which of the following is a measure of the amount of light a star directly emits? a. luminosity b. wavelength c. brightness d. intensity

Technology has affected regional settlement patterns in what ways? choose all that apply. climatic improvement strategies have improved crop productivity. mechanized agricultural methods have improved agricultural productivity. participation in the global economy has increased urbanization. population shifts from urban to rural areas has increased as a result of petroleum production. settlement areas have increased as a result of improved water storage and delivery systems.