On the given political outline map of the world, seven geographical features have been marked as A, B, C, D, E, F and G. Identify them with the help of the following information and write their correct names on the lines drawn near them:
A. An area of extensive commercial grain farming
B. An area of subsistence gathering
C. A major sea port
D. A major airport
E. A major sea port
F. A major area of nomadic herding
G. An inland waterway