Answer:
Land is the least effective because most disasters that occur are caused by either air or water...air pollution or flood.
Most people live in Moscow.
The most densely populated cities and towns are around Moscow.
Answer:
Asia and North-America
Explanation:
The Bering strait is a portion of about 47 miles (75 km) that separates Asia (Russia) and North-America (state of Alaska, USA). Let's remember that Alaska belonged to Russia and was bought by the US.
That straight is a place with very harsh and extremely violent weather fueled by cold Arctic water and winds.
20,000 years ago, that straight was solid ice and that's how human migrated from Asia to North America (and went further South afterwards).
I think the phrase you are looking for is "natural resources" - these include fresh water, food and fertile soil on which crops can easily be planted.
