Covalent compounds can be subdivided into polar and no polar compounds. In water, a polar molecule, the hydrogen electrons are not shared equally with the oxygen atoms; this results in a polar bond. Oxygen due to it's greater electro negativity pulls the electrons closer to its nucleus.
The Treaty of Versailles was the main causes of World War II due to the following reasons,Germany had to pay back 33 billion after WWI and forced to accept sole blame for the war in order to justify the reparations.
The treaty of versailles made germany take the blame for ww1 so they had to pay all the costs for it and sufferd a depression. Because of this Hitler got mad and wanted to take revenge so he started invading european countries and other things which made the countries mad and lead to ww2.