Rice
Pulses
Wheat
Oilseeds
Limestone caves
Crater lakes
Costal terraces
River valleys
leaf blight
leaf spot
leaf rust
rut
Nickel & Iron
Iron & Copper
Magnesium & Lead
Chromium& Iron
Egypt
Argentina
India
U.S.S.R
U.K.
U.S.A.
U.S.S.R.
Earth’s surface
Earth’s crust
Mountains
Ocean floor
Lower to higher altitudes
The surface of the sea to greater depths
One coast to another
One sea or ocean to another
100 Km
111 Km
151 Km
175 Km
1974
1976
1977
1978