Which one of the four M. A.I. N. causes of WW1 was the most influential in starting the war?

Difference in policies were to blame, although the immediate cause of World War one was the assassination of Austria's Archduke Franz Ferdinand. The war started mainly because of four aspects: Militarism, Alliances, Imperialism and Nationalism.

Explanation:

2. a land bridge connected asia and north america thousands of years ago.

4. crossing the land bridge would have been simple for the first migrants.

5. people might have crossed a land bridge while hunting animals.

stick up my a**