What led to a Sunni vs. Shi'a (Shi'it) division?

Plz 50 points answer only if you know and don't copy answer describe how the geography of the korean peninsula affected where people settled and how they lived.

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

At the casablanca conference, allied leaders signed an agreement to share military technology decided to launch an invasion of southern france agreed to accept only the unconditional surrender of the axis powers agreed to form a scientific team to create the atomic bomb