Subjects tell the listener and the reader whom or what the sentence is about. The subject is that part of a sentence which names a person, thing, or idea. e.g. Every complete subject contains a simple subject. The simple subject, which is a noun or pronoun, is the most important word in the complete subject.
The USPS considers a postcard to be any single rectangular piece of paper that is at least 3 1/2 inches high by 5 inches long by 0.007 inch thick' and no more than 4-1/4 inches high by 6 inches long by 0.016 inches thick.. The post office considers all papers outside of these dimensions to be letters.
The U.S. Postal Service allows customers to use the postcard rate for First-Class Mail for postcards that are at least 3.5 inches high by 5 inches wide but no more than 4.25 inches wide by 6 inches wide. As of April 2014, the postage rate for a postcard of this size is 34 cents. USPS also has a First-Class rate for large postcards that are no more than 6.125 inches high by 11.5 inches wide by 0.25 inches thick. These postcards cost 49 cents to mail as of April 2014.