The correct answer is letter D. Economy. Perestroika, as announced early in his years of leadership, was Gorbachev's policy to restructure the economy. At that moment, it's one of the crucial things to be taken care of.
Answer:
Five main sub-fields of geography
Biogeography ( study of plant and animal life and processes) Climatology (study of long term weather called climate and its effects on life) Geomorphology (earth's form and structure) Hydrology (study of all forms of water underground, over-ground and in the cloud.)
Similar - the corresponding angles are congruent
In a normal pile of sedimentary layers, the bottom layer would be oldest whereas the top would be the youngest.
Sedimentary rocks are formed when layers of sediment from the Earth are being deposited. That means that the bottom most layer would probably be also the first sediments that fell in the area, thus making the top layer the newest sediments.
Earthquakes and Tsunamis occur due to movement of tectonic plates, when the tectonic plates under the surface of earth move on the land, earth quakes occur, and when they move under water, tsunamis occur.
