Dough is a combination of water and flour and other additives. Dough can be made into crust and other stuff.
It is slightly thicker than traditional thin crust pizza. It usually has a thicker crust edge than thin as well.
Because they are preserved in a jar, and while most strawberries would rot, they last longer and to me, they taste the same.
It means to keep stay united. A good example of this was the American War Between the States also known as the Civil War. The war was fought to keep the states united into one country instead of two...
Preserve means keep, maintain. For example, to "preserve the Union" would mean to keep it from falling apart into independent states.