Please choose the correct ending to complete the given sentence: Education and Communications: [header] How to write an abstract [title] Write your paper first. [step] Even though an abstract goes at the beginning of the work, it acts as a summary of your entire paper. Rather than introducing your topic, it will be an overview of everything you write about in your paper.

Ending1: So before a general introduction to your topic, make sure that you know all about your subject. [substeps] For example, if you write about an urban housing problem but don't have an introduction to it yet, you can write about urban housing in a different section of your paper. Ending2: If you have a big paper, write it first. Think about spelling and punctuation mistakes if your paper is new to you. Ending3: Save writing your abstract for last, after you have already finished your paper. [substeps] A thesis and an abstract are entirely different things. Ending4: With an abstract, you actually present many ideas on your own, rather than just drawing them out. [substeps] It is important to lay out your main ideas in short paragraphs, rather than just sketching out them yet.

Answer format: ending1/ending2/ending3/ending4