Instead of submitting a copy of your teaching certificate with your application, you may submit verification that you are matriculated in a certification program (e.g., letter of acceptance, letter from advisor).
Expository writing is writing that seeks to explain, illuminate or 'expose' (which is where the word 'expository' comes from). This type of writing can include essays, newspaper and magazine articles, instruction manuals, textbooks, encyclopedia articles and other forms of writing, so long as they seek to explain.
When we read fiction novels, we are taking in narrative text. This type of text tells a story and generally uses a lot of emotion. The opposite of this is expository text, which exists to provide facts in a way that is educational and purposeful. The text is fact-based with the purpose of exposing the truth through a reliable source. True and deliberate expository text will focus on educating its reader. Other descriptors of exposition are clear, concise, and organized writing. Expository text gets to the point quickly and efficiently. The opposite of this is narrative text, which tells a story and generally uses a lot of emotion. Expository text is information-based text.