Although science has come a long way in this regard, burials still often cannot reveal when the deceased person died, or even when exactly he or she lived. It also cannot tell much about the person's true beliefs, although it may give clues as to the profession or religion of the deceased.
What the burial can or cannot tell depends significantly on the age, complexity, and preservation of the burial itself, but generally there is a great deal that a burial cannot tell historians.
Acquiring colonies to provide a favorable balance of trade.
Mercantilism was the theory that trade generates wealth and peer, so gathering colonies that stimulate trade would fall under mercantilism.
Because as a river is a corridor, it can help to travel and transport goods. It can also provide food as it might have fish.
The main reason why the march through Belgium helped France is that it won it some time (not much , the Battle of Belgium was only around 2 weeks long) to re-arrange their troops and specifically to move their troops further north to Paris and surroundings.