Car exhaust is an unhealthy result of fossil fuel use. Photo Credit exhaust fulmes image by bilderbox from Fotolia.com. Fossil fuels are among the most commonly used forms of energy in the world. Common fossil fuels include natural gas, coal and petroleum, which is refined to create gasoline.Although fossil fuels are strong sources of energy, their use can pose certain health problems if handled incorrectly.ar exhaust is an unhealthy result of fossil fuel use. Photo Credit exhaust fulmes image by bilderbox from Fotolia.com. Fossil fuels are among the most commonly used forms of energy in the world. Common fossil fuels include natural gas, coal and petroleum, which is refined to create gasoline.
First-Class Mail International is a USPS trademark. Note: The cost of postage will appear on all international shipping labels. Maximum weight for letters is 3.5 ounces. Maximum weight for large envelopes is 4 pounds.
Size and Price. For your letter to qualify as First-Class Mail, you must place it in a rectangular envelope. The weight restriction for First-Class Mail is 13 ounces, which is important to consider if you're enclosing hefty items such as magazines or photographs in your envelope.As of May 2015, you can send a letter by First-Class Mail by buying a Forever stamp, which costs 49 cents.he United States Postal Service reports that letters sent as First-Class Mail should take between one and three business days to reach their destination. This duration depends on how far your letter must travel to its destination.