a) It's caused by bacteria. Pericoronitis is an infection. It's caused by normal oral bacteria, like those found in dental plaque. It's the gum relationship around a partially-erupted tooth that allows pericoronitis to occur.
A futures exchange or futures market is a central financial exchange where people can trade standardized futures contracts; that is, a contract to buy specific quantities of a commodity or financial instrument at a specified price with delivery set at a specified time in the future. These types of contracts fall into the category of derivatives. The opposite of the futures market is the spots market, where trades will occur immediately (2 business days) after a transaction agreement has been made, rather than at a predetermined time in the future.
With currency futures, the price is determined when the contract is signed, just as it is in the forex market, only and the currency pair is exchanged on the delivery date, which is usually some time in the distant future. transferable futures contract that specifies the price at which a currency can be bought or sold at a future date. Currency future contracts allow investors to hedge against foreign exchange risk.