What percentage of the total Earth’s population growth is in underdeveloped countries?

Identify the youngest layer in the figure ( have to click one letter)

What was the main purpose of the "four freedoms" speech?

The images show two different fronts. which fronts are shown? item a shows a cold front, and item b shows a warm front. item a shows an occluded front, and item b shows a cold front. item a shows a warm front, and item b shows a stationary front. item a shows a stationary front, and item b shows an occluded front.