The start of world war 1 can be traced to which of these factors?

What would lead a historian to consider two events to have a relationship of correlation rather than causation?

What led to the environmental damage that caused the dust bowl? 1. desert winds emerging from the southwest 2. rotating crops every year and having fallow land 3.overplanting throughout the great plains 4.a year-long drought

What happened as a result of the colonial victory at saratoga