They were able to grow their own food which was a plus for them since the rainfall helped increase their chances of getting food. Hopefully, this helps you. ^^
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.
