1.
the surroundings or conditions in which a person, animal, or plant lives or operates.
Environment can be defined as a sum total of all the living and non-living elements and their effects that influence human life.
Answer:
1. War and insecurity 2. Economic crisis (poverty) 3. Overpopulation
Explanation:
1. War and insecurity - as example Syrian crisis and war against ISIS
2. Economic crisis (poverty) - mass immigration from Poland to USA in the late XIX and early XX century.
3. Overpopulation - mass immigration to Europe from African countries in the last few decades.
They wanted to find ways to benefit ordinary citizens.
The Mongol Empire lasted only 100 years.
The Mali Empire lasted a little more than 300 years.
Realised that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.
