Clastic and chemical sedimentary rocks
Explanation:
Clastic sedimentary rocks form from the clustering together of weathered rocks, while chemical sedimentary rocks form from the precipitation or separation of dissolved minerals from water.
Answer:
Around the world the most significant restriction on access to potable water is money. While access to raw water sources, clean or otherwise, is important, the purification process itself is expensive. Once water has been rendered potable, it is important that it be delivered without reintroducing contamination.
I would say that the US and the Soviet Union at the end of WWII withdrew their troops as soon as a demilitarized zone was created. Also, I am sure they would require a peace treaty to be signed with Germany before withdrawing troops.
