I'm not sure what "4m" means, but I think semi-sweet just refers to chocolate with a high cocoa content (70%+, generally) and a low sugar content (less than about 30%) - dark chocolate chocolate chips, basically.
Curvature chocolate is a premium version of chocolate ( otherwise known as compound chocolate) it has little or no vegetable oils present in the mix, also the curvature is cooked at a higher and more constant temperature than compound chocolate and cooled at a lower temperature as well.
just bigger than a full sized football pitch
The chocolate undergoes a state change from solid to liquid as its temperature exceeds the freezing point of the chocolate. Chocolate molecules are liberated into the air. When the molten chocolate is transferred to a food item, or to a mold, a heat transfer from the chocolate to the item it was placed on or in takes place, followed by a state change from liquid to solid as the temperature of the chocolate is reduced below its freezing point. When the chocolate is placed in the mouth of a chocolate eater, acetylcholine and cholinesterase transmitted along the nerves leading from the taste buds to the brain signal to the brain that something tasty has been consumed. This leads to release of various biochemical transmitters that signal satisfaction, unless you buy really cheap chocolate and then these same transmitters will signal, "what the hell were you thinking, the good stuff was only a buck more!" Some people who melt chocolate experience temporary enlargement of the bank account since chocolate, properly melted and formed into salable products, is a valuable and desirable item of commerce. Caution must be exercised since excessive melting of chocolate can lead to increased mass in the chocolate melter. A gooey amazingness that can go on pretty much anything edible. Or an oozing, flowing, melted, liquid gold that you can eat. Look up "tempering chocolate." Check Related Links for a cool website, if you are interested in chemistry or experiments with chocolate.
Chocolate is eaten worldwide, and it is almost impossible to tell how much is eaten every day. So, unfortunately, i cannot give you a strait answer. The amount of chocolate YOU eat everyday increases by stress. Studies have shown that when you are stressed and eat chocolate, it gives you a soothing, calm feeling. That is also why it is addictive. After eating chocolate you feel happy. So you wan't more. It is very hard to stop eating chocolate, once you have been addicted. When you stop eating chocolate, it leaves you sad again. So you decide just a little won't hurt. That's why it's so hard to stop.