In recent years, Russia has advanced its military capabilities in the Arctic, reopening old military bases that had been abandoned following the collapse of the Soviet Union in 1991, and bolstering the Russian Navy's prestigious Northern Fleet that oversees operations and defense in the region.
Answer:
d) a wall that was built as a boundary but is no longer considered a boundary
Explanation:
Take the Berlin Wall for example, it is a relic boundary because it no longer splits Germany into East and West Germany.
The definition for a relic boundary is a boundary that no longer exists as a boundary just a cultural landscape.
There are three types of fossil fuels: Oil, coal and gas.
Let's look into their formation one by one:
Oil: Dead plankton such as microorganisms and plants was buried under the sea million years ago, it accumulate over time to become oil, also known as petroleum,
Coal: Plants were dead and broken down by bacteria over time, carbon dioxide and methane were produced. After million years, the dead flora accumulated to become peat and undergone compaction, becoming coal.
Gas: This is formed along oil, and again produced by dead organisms. It is mostly formed during decomposition, and mostly made up of methane.
Hope it helps!
C because graduated terrace steps are commonly used to farm on hilly or mountainous terrain. Terraced fields decrease both erosion and surface runoff, and may be used to support growing crops that require irrigation, such as rice. ( It basically means that terraced farming is farming over steps and using rain to wash away old soil so that's where the wet part comes in)