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.
Quick Answer. According to the USPS, the minimum size of an envelope that can be mailed is 5 inches long by 3 1/2 inches high by 0.007 inches thick. The regulations also state that envelopes must be rectangular and not larger than 11 1/2 inches by 6 1/8 inches by 1/4 inches. Continue Reading.