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.
Postcard Sizes. Postcards have been around nearly as long as postal services and are produced in a wide range of sizes, with some even being special shapes, for instance circular. However there are some recognised sizes for the standard postcard. Although the general consensus is that the dimensions of an international standard postcard are A6 size, 148 x 105 mm or 5.8 x 4.1 inches.