2. Introduce yourself. You have never met the reader. He knows nothing about you. If you want others to trust you, hire you, or let them see you and talk, there is no other way. The only way is to sell yourself and recommend yourself. Therefore, when writing a letter, you should express yourself appropriately, attract him with your achievements, strengths, advantages and even personality, and make him feel that you are worth talking about or trying.
3. Competitiveness. Job hunting is competition. The company or unit you apply for may be a very famous and promising place, and everyone wants to go in. If you want to win in the competition, you must be outstanding and different. This should be fully reflected in your letter. You should believe the true nature of the letter and let the readers (often the person in charge of the company or unit) see the true nature of the letter, so that you can get the upper hand in the competition. Of course, you may also fail. Therefore, there is no need to "hang from a tree." You might as well write several cover letters selectively and send them separately, so as to find a more ideal or satisfactory job in another company or unit.