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.
First-Class Mail is a USPS trademark. 1  The minimum size for First-Class Mail is 5 inches long, 3-1/2 inches high and 0.007 inches thick. 2  The maximum size is 11-1/2 inches long, 6-1/8 inches high, and .75 inches thick. 3  The maximum weight for letters is 3.5 ounces. The maximum weight for envelopes and packages is 16 ounces when you create and print your shipping label on eBay. You can send pieces over 16 ounces as Priority Mail (see below). For more information, please see First-Class Mail prices.